Irresistible Leek and Mushroom Quiche: Your Guide to a Creamy, Cheesy, and Flaky Vegetarian Delight

Indulge in the culinary perfection of this Leek and Mushroom Quiche, a truly delightful vegetarian dish that promises a symphony of flavors and textures. Each bite offers a harmonious blend of creamy, cheesy richness, perfectly complemented by the earthy notes of mushrooms and the subtle sweetness of leeks. Nestled within a homemade, incredibly flaky shortcrust pastry, this quiche is a versatile masterpiece, ideal for elevating any meal of the day – be it a comforting breakfast, a sophisticated brunch, a satisfying lunch, or a light yet fulfilling dinner.

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Why You’ll Adore This Leek and Mushroom Quiche Recipe

There are countless reasons to fall in love with this spectacular Leek and Mushroom Quiche. It’s not just a dish; it’s an experience! This vegetarian delight offers a rich, meatless alternative that doesn’t compromise on flavor or satisfaction. Packed with wholesome vegetables, it features a generous mix of tender leeks and earthy mushrooms, all enveloped in a luxurious, fluffy egg custard. The entire creation is then encased in a delicate, buttery, and irresistibly flaky pastry shell, making every bite a true indulgence.

The carefully chosen combination of sautéed mushrooms, caramelized leeks, and savory cheddar cheese creates an unbelievably rich and complex flavor profile. The earthy depth of the mushrooms harmonizes beautifully with the subtle sweetness of the leeks, while the sharp, salty notes of cheddar cheese tie everything together in an amazingly flavorful package that is simply hard to resist. It’s a testament to how simple ingredients can create extraordinary taste.

Beyond its incredible taste, this quiche is a marvel of versatility. Quiches are the ultimate chameleon of dishes, perfectly suited for literally every meal of the day. Serve it warm for a comforting breakfast or a sophisticated brunch centerpiece. Enjoy a slice at room temperature for a quick and satisfying lunch, or pair it with a fresh salad for a light yet elegant dinner. Its adaptability also makes it an excellent choice for meal prep; you can bake it in advance and store it in the refrigerator, or even freeze individual slices for future cravings. This makes it an ideal dish for busy weeknights, potlucks, or holiday gatherings.

If you’re already a fan of savory tarts and quiches, you’ll surely enjoy exploring similar recipes such as this delightful Gruyère and Leek Tart, a classic Leek Quiche, or the equally delicious Spinach and Mushroom Quiche. Each offers its unique charm, but all deliver on comfort and flavor.

Essential Ingredients for Your Leek and Mushroom Quiche

Crafting this incredible quiche begins with a selection of fresh, high-quality ingredients. Each component plays a vital role in achieving that perfect balance of flavor and texture. Here’s a detailed look at what you’ll need:

For precise quantities, please refer to the detailed recipe card below.

For the Flaky Savory Shortcrust Pastry:

• All-Purpose Flour & Fine Table Salt: The foundation of our pastry. Using plain or all-purpose flour provides the necessary structure. A pinch of fine table salt is crucial for seasoning the crust and balancing the flavors of the filling. Feel free to experiment by adding your favorite spices, seasoning, or dried herbs (like a touch of garlic powder or onion powder) to the dry ingredients for an extra layer of flavor in your pastry.
• Very Cold Unsalted Butter: This is the secret to a truly flaky pastry. Ensure your butter is straight from the fridge and cut into small cubes. The cold butter creates pockets of steam during baking, which results in those desirable flaky layers. Unsalted butter gives you control over the overall saltiness of the dish.
• Very Cold Ice Water: Similar to the butter, extremely cold water is essential. It helps keep the butter firm and prevents the gluten in the flour from developing too much, which would lead to a tough crust. For an even richer pastry shell, you could replace a portion of the water with an equal amount of very cold full-fat milk or heavy cream.

For the Rich Mushroom & Leek Filling:

• Custard Base (Eggs & Heavy Cream): The heart of any quiche is its creamy custard. We use large, room-temperature eggs for a smoother, more emulsified mixture, combined with thickened or heavy cream (with at least 30% fat content). The high fat content of the cream is vital for achieving that luxurious, velvety texture and rich flavor. Avoid using fat-reduced or light cream, as it will compromise the quiche’s signature creaminess and overall taste.
• Aromatic Seasoning: Flavor is key! Our chosen blend includes essential Salt and freshly ground Pepper to enhance the natural tastes. Dried Herbs (such as a classic mix of oregano and parsley) add an aromatic depth. Minced Garlic provides a pungent, savory base. Don’t hesitate to personalize this – thyme, rosemary, or even a pinch of nutmeg can be wonderful additions.
• Fresh Vegetables (Leeks & Mushrooms): The stars of our filling! You’ll need finely chopped Leeks and thinly sliced Mushrooms. For the mushrooms, small White Cup Mushrooms are excellent, but feel free to explore other varieties like Cremini (Baby Bellas) for a deeper flavor, or even wild mushrooms for a more gourmet touch. In this recipe, the leeks are gently pre-cooked until beautifully soft and translucent to bring out their sweetness, while the mushrooms are added raw to the quiche, where they will release their moisture and cook perfectly within the custard.
• Grated Cheese: For a comforting, savory kick, Cheddar Cheese is a fantastic choice, offering a sharp and satisfying flavor. However, the beauty of quiche lies in its adaptability. You can easily substitute it with other favorites like creamy Mozzarella, nutty Gruyère (a traditional choice for French quiches), or even crumble in a soft cheese like tangy Goat’s Cheese or salty Feta for a different dimension.

Optional Enhancements:

• Protein Boost: For those who enjoy a heartier quiche, consider adding cooked and crumbled Ham, crispy Bacon bits, or your favorite lean deli meat. Ensure any added meat is pre-cooked and drained of excess fat.
• Fresh Herb Garnish: While dried herbs are incorporated into the filling, a sprinkle of fresh herbs like finely chopped Parsley or chives just before serving adds a vibrant burst of color and a fresh, aromatic finish. You can also mix some fresh herbs directly into the egg custard base for an intensified flavor.

Step-by-Step Guide: How to Craft Your Perfect Leek and Mushroom Quiche

Creating this delicious quiche involves a few key stages, each contributing to the final delectable result. Follow these instructions carefully for a quiche that’s as beautiful as it is tasty.

1. Preparing Your Flaky Savory Pastry

A truly exceptional quiche starts with an outstanding crust. This shortcrust pastry is remarkably easy to make, especially with the help of a food processor. If you prefer a hands-on approach, detailed instructions for making it by hand can be found in my comprehensive Savoury Shortcrust Pastry recipe.

• Combine Dry Ingredients and Butter (Photo 1 & 2): Begin by placing your all-purpose flour and fine table salt into the bowl of your food processor. Pulse a few times to ensure they are well combined. Next, add the very cold, cubed unsalted butter. Pulse the mixture for approximately 30 seconds to 1 minute. Your goal is to achieve very small, pea-sized crumbs of butter that are evenly distributed throughout the flour. This “sandy” texture is key for a flaky crust.
• Incorporate Cold Water (Photo 3 & 4): With the food processor running on a low setting, slowly drizzle in the very cold water, a tablespoon at a time. Continue mixing until a rough dough just begins to come together. Avoid over-processing, as this can develop the gluten too much and make the pastry tough.

Checking for Readiness: To determine if your savory pastry is ready, pinch a small amount of the crumbly mixture between your fingers. If it holds together easily and forms a cohesive, smooth dough, it’s perfect. If it remains too dry and crumbly, add a tiny bit more cold water, a teaspoon at a time, and pulse again until the desired consistency is reached. Remember, the exact quantity of water can vary slightly depending on factors like flour brand and humidity, so always add it gradually.

2. Rolling, Lining, & Par-Baking the Pastry Shell

Properly preparing and par-baking your crust is crucial for preventing a soggy bottom and ensuring a beautifully golden, sturdy foundation for your quiche.

• Shape and Chill the Dough (Photo 5 & 6): Turn the freshly made pastry dough out onto a large sheet of baking or parchment paper. Gently gather it into a cohesive ball, then flatten it slightly into a disk. Cover this disk with a second sheet of baking paper and roll it out evenly into a large round, approximately 4mm (or 1/6 inch) thick. Transfer the rolled dough (still between the parchment paper) onto a flat baking tray and refrigerate it for at least 1 hour. This crucial chilling period allows the gluten to relax, which prevents the pastry from shrinking excessively during baking, and ensures the butter remains very cold. You can prepare this step up to 24 hours in advance.
• Line the Quiche Pan (Photo 7 & 8): After chilling, remove the pastry from the fridge and let it sit at room temperature for about 5 minutes to soften just enough to be pliable. Carefully peel off one sheet of baking paper. Invert the dough into a 25 cm (10-inch) quiche pan that is about 4 cm (1.5-inch) deep. Pans with a removable bottom plate are highly recommended, as they make unmolding the baked quiche incredibly easy. Gently press the pastry into the pan, ensuring it’s completely flush with the bottom and sides, carefully working it into the corners. Use a sharp knife to trim away any excess dough from the edges. Finally, use a fork to dock (prick small holes) the bottom of the pastry; this allows steam to escape during baking and prevents the crust from puffing up.
• Second Chill and Par-Bake: Once lined, return the tart pan with the pastry to the refrigerator for at least 2 hours, or ideally, overnight. The longer it rests and chills, the less shrinkage you’ll experience in the oven. When ready to bake, preheat your oven to 160°C (325°F). While the oven heats, place the chilled quiche pastry in the freezer for about 10-15 minutes – this quick freeze helps set the butter and maintain the shape. Line the pastry shell with baking paper and fill it with baking weights (such as ceramic pie weights, dry rice, or dried beans). Par-bake for 15 minutes. After this initial bake, carefully remove the weights and baking paper, then continue baking for another 10 to 15 minutes, until the crust is lightly golden and dry. Set aside to cool completely before filling.

3. Preparing Your Flavorful Quiche Filling

With your pastry par-baked and cooling, it’s time to assemble the delicious heart of your quiche: the leek and mushroom filling and the creamy egg custard.

• Prepare the Leeks (Photo 9): Begin by thoroughly washing and cleaning your leeks, ensuring all dirt is removed from between their layers. Thinly chop the white and light green parts of the leeks. Heat a large saucepan over medium heat with a tablespoon of olive oil. Add the minced garlic, then the chopped leeks. Sauté for 5 to 10 minutes, stirring occasionally, until the leeks become wonderfully soft, tender, and translucent. This process brings out their natural sweetness. Remove from heat and set aside to cool slightly.
• Prepare the Mushrooms: Gently peel your mushrooms or use a brush to clean off any dirt. Slice them thinly. Set these aside; they will be added raw to the quiche, cooking perfectly within the custard.
• Whisk the Custard (Photo 10 & 11): In a large mixing bowl, combine the room-temperature eggs, heavy cream, salt, pepper, and dried herbs. Whisk these ingredients together until you achieve a smooth, homogenous batter. Be careful not to over-whisk; excessive whisking can incorporate too much air, which might cause the quiche to puff up significantly in the oven and then deflate.
• Add the Cheese (Photo 12): Finally, add the grated cheddar cheese to the egg mixture. Whisk gently until the cheese is evenly distributed throughout the custard. If you wish to have a visibly cheesy top, you can reserve a small amount of the grated cheese to sprinkle over the quiche just before baking.

4. Assembling and Baking Your Mushroom Leek Quiche

With all your components ready, it’s time for the grand assembly and the magical transformation in the oven!

• Layer the Veggies (Photo 13): Evenly spread the cooked leeks and thinly sliced raw mushrooms over the bottom of your cooled, par-baked pie crust. Try to alternate between the two vegetables to ensure an even distribution of flavor in every slice. If you desire a rustic, visual appeal, you can set aside a small portion of the vegetables to arrange decoratively on top of the quiche before pouring the custard.
• Pour and Top (Photo 14): Carefully pour the prepared egg and cheese mixture over the layered vegetables in the pastry shell. If you reserved any mushrooms, leeks, or cheese, now is the time to artfully arrange them on top of the liquid filling.
• Bake to Perfection: Gently transfer the leek and mushroom quiche into your preheated oven. Bake for approximately 40 to 50 minutes. The exact baking time can vary depending on your oven’s calibration and the specific depth and size of your quiche pan, so keep a close eye on it. The quiche is fully baked and set when the filling appears golden brown and no longer jiggles significantly in the center when the pan is gently shaken. Once baked, remove the quiche from the oven and allow it to cool down slightly on a wire rack before carefully removing it from the quiche pan. Serve warm or at room temperature.

Frequently Asked Questions About Leek and Mushroom Quiche

Top Tips for Quiche Perfection

• Embrace the Chill Time for Pastry: When preparing your homemade quiche pastry, patience is truly a virtue. Give the dough ample time to rest and chill, both after mixing and especially after lining the quiche pan. For the absolute best results – a pastry that holds its shape beautifully and shrinks minimally – allow the lined pastry shell to chill in the refrigerator overnight before moving on to par-baking and filling. This extended chilling period relaxes the gluten and keeps the butter extremely cold, resulting in an exceptionally flaky and tender crust.
• Check for Doneness Like a Pro: To determine if your quiche is perfectly baked, gently give the quiche pan a slight shake. Observe the center of the filling. A properly baked quiche will show very little to no movement or “jiggling” in the middle. The edges should be set and lightly golden, and the center should be firm yet still have a slight, delicate give.
• Prevent Over-Browning: If you notice the top of your quiche or the edges of the pastry are browning too quickly before the filling has completely set, don’t fret! Simply cover the quiche loosely with a sheet of aluminum foil. This will protect the top from further browning while allowing the filling to continue cooking through. You might also consider slightly reducing your oven temperature by 10-15 degrees Celsius (25-50 degrees Fahrenheit) for the remainder of the baking time.

Storing & Freezing Your Leek and Mushroom Quiche

This quiche is not only delicious fresh from the oven but also makes a fantastic make-ahead meal. Here’s how to store and freeze it to maintain its quality:

• Storing Leftovers: The baked quiche can be served immediately, or you can store any leftovers in the refrigerator for up to 2-3 days. To keep it fresh and prevent it from absorbing any unwanted odors from your fridge, ensure it is tightly covered with plastic wrap or aluminum foil.
• Making in Advance: If you plan to make the quiche ahead for an event or future meal, I recommend slightly under-baking it by about 5-10 minutes. This ensures that when you reheat it in the oven before serving, it finishes cooking perfectly without drying out or over-browning.
• Reheating for Best Results: The optimal way to reheat a whole quiche or larger slices is in the oven. Preheat your oven to a moderate temperature (around 160°C/325°F) and bake until warmed through, usually 15-25 minutes depending on size. While individual slices can be reheated quickly in the microwave, be aware that this method tends to make the delicious shortcrust pastry a bit softer and potentially soggy, losing some of its crispness.
• Freezing for Longer Storage: To freeze the quiche, allow it to cool completely after baking. Once cooled, transfer the entire quiche (or individual slices) onto a flat tray and place it in the freezer until it is fully frozen solid. This prevents it from getting squashed. Once frozen, remove it from the tray and wrap it thoroughly with a layer of plastic wrap, followed by a layer of aluminum foil, ensuring it’s airtight to prevent freezer burn. Individual slices can also be stored in freezer-friendly bags or rigid containers. Frozen quiche can be kept for up to 2-3 months. To reheat from frozen, thaw overnight in the refrigerator, then reheat in the oven as described above.

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Recipe Card: Leek and Mushroom Quiche

Leek and Mushroom Quiche

4.82 from 11 votes

Perfect for Breakfast, Lunch, or a Light Dinner, this Leek and Mushroom Quiche is deliciously creamy, cheesy, and packed with irresistible flavors. Featuring a homemade Flaky Butter Pastry and a savory Mushroom and Leek Filling, this vegetarian quiche is an ideal dish to serve at any meal of the day, offering comfort and sophistication in every slice!

Servings:
8 servings

Author:
Sylvie

Prep Time
30 minutes mins

Cook Time
1 hour hr

Resting Time
2 hours hrs

Total Time
3 hours hrs 30 minutes mins

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Ingredients

Savoury Shortcrust Pastry

• 200 gr Plain / All-Purpose Flour
• 1/4 teaspoon Fine Table Salt
• 100 gr Unsalted Butter, very cold, cut into small cubes
• 65 ml Water, very cold / ice water

Quiche Filling

• 2 small Leeks, finely chopped
• 1/2 tablespoon Olive Oil
• 1 teaspoon Minced Garlic
• 200 gr White Cup Mushrooms, or your preferred variety of mushrooms, thinly sliced
• 4 large Eggs, at room temperature
• 300 ml Thickened / Heavy Cream, 30% fat content
• 1 1/2 teaspoon Fine Table Salt
• 1/2 teaspoon Pepper
• 1 teaspoon Dried Herb Mix, e.g., oregano and parsley
• 40 gr Grated Cheddar Cheese, or your choice of savory cheese

Instructions

Quiche Pastry

• Place the Flour and Salt in the bowl of your Food processor and pulse to mix. Add the very cold Butter, cut into small cubes, and pulse for 30-60 seconds until you get a thin crumb texture (like coarse sand). Slowly add the cold Water (approx. 65ml) while mixing until the dough starts to come together into a rough ball (see note 1).
• Gather the dough into a disk and transfer it between two sheets of baking paper. Roll the Pastry into a large round, about 4mm (1/6 inch) thick, then place on a flat tray and refrigerate for at least 1 hour (or up to 24 hours in advance) to chill thoroughly.
• Remove the pastry from the fridge and let it sit at room temperature for about 5 minutes to soften slightly. Remove one sheet of baking paper and carefully invert the pastry into a 25 cm (10-inch) wide, 4 cm (1.5-inch) deep quiche pan with a removable bottom.
• Gently press the pastry down the sides and into the bottom corners of the pan, ensuring it’s completely flush. Use a sharp knife to trim off any excess dough from the edges. Dock the bottom of the pastry (make small holes with a fork) to prevent puffing. Place the pastry-lined pan back in the refrigerator to chill for at least 2 hours, preferably overnight, for best results and to prevent shrinkage.
• Preheat your oven to 160°C (325°F). While the oven heats, place the chilled quiche pastry in the freezer for 10-15 minutes. Line the pastry with baking paper and fill with baking weights (such as pie weights, rice, or dry beans). Par-bake for 15 minutes. Remove the weights and baking paper, then bake for an additional 10 to 15 minutes, until the crust is lightly golden and dry. Set aside to cool completely.

Filling Preparation

• Wash and thinly chop the Leeks (white and light green parts). Heat a large saucepan with Olive Oil, add the minced garlic, then the chopped leeks. Cook on medium heat for 5 to 10 minutes, stirring occasionally, until the leeks become soft, tender, and translucent. Set aside to cool.
• Clean the mushrooms (brush or peel) and cut into thin slices. Set aside.
• In a large mixing bowl, combine the Eggs (at room temperature), Cream, Salt, Pepper, and Dried Herbs. Whisk until smooth. Add the Grated Cheese and whisk gently until combined. Optionally, reserve a small amount of cheese to sprinkle on top before baking.

Assembling and Baking the Quiche

• Evenly spread the cooled, cooked Leeks and thinly sliced Mushrooms over the bottom of your cooled, par-baked pie crust. Alternate between the two vegetables to ensure distributed layers. Optionally, keep a small amount of veggies aside for topping.
• Carefully pour the prepared egg and cheese mixture over the vegetables. Optionally, top with any remaining mushrooms, leeks, and reserved cheese.
• Place the quiche in the preheated oven and bake for 40 to 50 minutes (see note 2), or until the filling is fully baked, set, and lightly golden. The center should show very little jiggle when gently shaken. If browning too quickly, cover with foil. Leave to cool down slightly on a wire rack before carefully removing from the quiche pan and serving warm or at room temperature.

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Notes

This recipe is designed for a 25 cm (10-inch) wide Quiche Pan that is approximately 5 cm (2 inches) deep.

For a more in-depth understanding of the quiche pastry, including extra tips and a detailed step-by-step process with visuals, please refer to my dedicated Savoury Shortcrust Pastry recipe.

1. Pastry Water Quantity: The exact amount of cold water needed for the pastry can vary based on the specific brand of flour you use and even the humidity in your kitchen. It is crucial to add the water very slowly, a tablespoon at a time, and mix well after each addition. Stop as soon as the dough just begins to come together into a cohesive mass to avoid overworking it.
2. Quiche Doneness: Baking times can differ significantly depending on your individual oven’s calibration and the size/depth of your quiche pan. Therefore, it’s essential to keep a close eye on your quiche. The quiche is perfectly baked when the filling no longer visibly jiggles when you gently shake the pan. If you notice the quiche or its crust is browning too quickly before the center is set, loosely cover it with aluminum foil and continue baking until it is ready.

Nutrition (per serving)

Calories: 393kcal |
Carbohydrates: 25g |
Protein: 9g |
Fat: 29g |
Saturated Fat: 17g |
Polyunsaturated Fat: 2g |
Monounsaturated Fat: 8g |
Trans Fat: 0.4g |
Cholesterol: 168mg |
Sodium: 595mg |
Potassium: 229mg |
Fiber: 1g |
Sugar: 3g |
Vitamin A: 1428IU |
Vitamin C: 4mg |
Calcium: 99mg |
Iron: 2mg