Meaty portobello mushrooms take center stage in this vegetarian twist on the classic Philly cheesesteak. Sautéed onions and bell peppers are combined with savory, browned portobellos, topped with provolone and tucked into toasted garlic bread rolls for a satisfying, flavor-packed sandwich.
Veggie Philly cheesesteak sandwiches are perfect for mushroom lovers and are easy to make vegetarian or vegan by swapping the dairy for plant-based alternatives.
Pan-seared portobello mushrooms, slowly caramelized onions, crisp-sweet peppers, and melted provolone create a deep, well-rounded flavor profile that makes this sandwich a satisfying meat-free option.
How to make a veggie Philly cheesesteak
Start by caramelizing the onions. Heat a large skillet over medium-low heat and add 1 tablespoon of butter. Add the thinly sliced onion and a pinch of fine sea salt. Thinner slices caramelize faster, and the salt helps the onions release moisture so they brown more quickly. Cook for about 20 minutes, stirring occasionally, until the onions are a deep golden color.
Remove the onions from the skillet. Increase the heat to medium, add 2 tablespoons of cooking oil, and add the thinly sliced portobello mushrooms with a pinch of salt. The salt helps draw out moisture so the mushrooms can brown and develop a meaty texture. Cook until they have released their liquids and started to caramelize, about 8–10 minutes.
Return the caramelized onions to the pan, add the sliced red and green peppers, and a tablespoon of tamari. Sauté for 2–3 minutes until the peppers are warmed but still slightly crisp. Taste and adjust seasoning with salt and pepper.
Preheat your oven to 400°F to toast the rolls and melt the cheese. Mix 1.5 tablespoons of butter with 2 crushed garlic cloves and brush the garlic butter on the cut sides of each roll. Toast the rolls in the oven for 3–5 minutes, until the butter melts and the bread starts to crisp.
Fill the toasted roll with the mushroom and vegetable mixture, top with thin slices of provolone, then return the sandwich to the oven until the cheese is melted and bubbly. Remove and serve hot.
Tips for the Best Veggie Philly Cheesesteak
Slice onions thinly so they caramelize faster and evenly.
If you prefer a lighter filling color, remove the mushroom gills before slicing; they can darken the mixture.
Use a large skillet when cooking mushrooms so they have ample surface area to brown rather than steam.
Dietary Considerations
This veggie Philly cheesesteak suits several dietary preferences:
- Vegetarian
- Vegan — replace the butter and provolone with vegan butter and vegan cheese
- Low carb / keto — skip the roll and serve the mushroom filling in lettuce wraps
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More Comforting Vegetarian Favourites You’ll Love!
If you enjoy this veggie Philly cheesesteak, try other vegetarian mains that highlight bold flavors and satisfying textures.
Veggie Philly Cheesesteak
Ingredients:
- 1/2 large white onion – thinly sliced
- 1 Tablespoon butter
- 2 large portobello mushrooms – thinly sliced
- 2 Tablespoons cooking oil
- 1/4 green pepper – sliced
- 1/4 red pepper – sliced
- 1 Tablespoon tamari
- 1 large French sub roll (or 2 smaller rolls)
- 2 cloves garlic – crushed
- 1.5 Tablespoons butter (for the roll)
- 3 ounces thinly sliced provolone cheese
- Salt and pepper to taste
Instructions
- Heat a large non-stick pan over medium-low heat and add 1 tablespoon butter. When hot, add the sliced onions and a pinch of salt.
- Cook the onions about 20 minutes, stirring occasionally, until they turn deep golden. Remove from the pan.
- Increase heat to medium, add cooking oil, then add the sliced portobellos. Cook about 8–10 minutes until they release moisture and begin to brown.
- Add tamari, and a splash of water if needed, then return the onions and add the peppers. Sauté about 2–5 minutes until peppers are tender-crisp. Season with salt and pepper.
- Preheat oven to 400°F.
- Mix crushed garlic with 1.5 tablespoons butter and brush on both cut sides of the roll. Bake 3–5 minutes until the butter melts and the roll begins to toast.
- Remove the roll from the oven, pile on the mushroom mixture, and top with provolone slices.
- Return the sandwich to the oven until the cheese melts. Remove and serve immediately.
Nutrition
Carbohydrates: 27 g
Protein: 17 g
Fat: 41 g
*Nutritional information is estimated and may vary.