Craving the savory, cheesy experience of a Philly-style cheesesteak but want to skip the meat? This Vegetarian Cheesesteak swaps thinly sliced portobello mushrooms and onions for steak while keeping the bold, satisfying flavors intact.
The homemade cheese sauce is creamy and indulgent, pairing perfectly with the meaty texture of roasted portobellos. A simple marinade adds a smoky, savory note that helps the mushrooms mimic the classic cheesesteak profile. Finish everything on a buttered, toasted hoagie roll for an easy, comforting meatless sandwich.
These mushrooms make an excellent substitute for steak (try a grilled portobello steak for another option), and this Vegetarian Philly Cheesesteak is quick to prepare: about 45 minutes total, using a sheet pan and a small pot for the sauce—minimal cleanup and big flavor.
Vegetarian Philly Cheesesteak Ingredient Highlights
This sandwich features a quick savory marinade for the vegetables, roasted portobellos and onions, and a rich white American cheese sauce—all served on a toasted hoagie roll.
Liquid smoke is optional but highly recommended for a smoky depth that helps the mushrooms more closely resemble grilled meat. If you don’t have it, omit it and still enjoy a flavorful result.
White American cheese melts smoothly and produces the best texture for the sauce. Regular American cheese works well too; if using individually wrapped slices, you’ll need about four. Any dairy milk or unsweetened, unflavored non-dairy milk is fine. Use unsalted butter because American cheese can be salty. For mustard, choose grainy or smooth Dijon based on preference.
Portobello Philly Cheesesteak Tips and Tricks
How to Make a Vegetarian Philly Cheesesteak with Portobello Mushrooms
Start by rinsing and slicing your portobello caps into roughly ½-inch strips. Core and thinly slice a yellow onion and, if using, a red bell pepper. Even, thin slices help the vegetables roast evenly and develop caramelized edges.
Arrange the sliced vegetables on a lined baking sheet with space between pieces for proper roasting. Whisk together olive oil, soy sauce, maple syrup, and liquid smoke and drizzle it over the vegetables. Season with salt and pepper, then toss to coat evenly.
Roast the vegetables at 400°F for about 25–30 minutes, until tender and slightly browned. While the veggies roast, prepare the cheese sauce. Use a small pot and keep the heat very low—if your stove has a warm setting, use it. Combine the white American cheese, milk, butter, Dijon mustard, and garlic powder and stir frequently until the cheese melts into a smooth sauce. Cooking low and slow prevents separation and gives you the best texture.
When the vegetables are finished, remove the baking sheet and turn the oven off. Butter the hoagie roll and place it in the still-warm oven for 3–5 minutes to toast. Watch closely so it doesn’t overbrown.
Assemble the sandwich by piling the roasted mushrooms and onions onto the toasted hoagie, then generously spooning the warm cheese sauce over the top. Serve immediately for the best texture and flavor.
How to Properly Store and Reheat Vegetarian Cheesesteak
You’ll likely have leftover cheese sauce—save it as a dip for pretzels or chips. Store the sauce covered in the refrigerator for up to 4 days and reheat gently on the stove over low heat, stirring frequently.
Store leftover roasted vegetables in an airtight container in the fridge for up to 4 days. Reheat them on a baking sheet in a 400°F oven for 8–10 minutes to refresh their texture.
If you have a leftover assembled sandwich, keep it covered in the refrigerator and reheat in the oven or toaster oven at 400°F for 8–10 minutes, or in an air fryer at 350°F for 4–6 minutes to warm through and re-crisp the roll.
Vegetarian Philly Cheesesteak with Portobellos
Marley Goldin
Ingredients
Philly Cheesesteak
- 1 large portobello mushroom cap
- ½ large yellow onion
- ½ large red pepper (optional)
- 1 tablespoon olive oil
- 1 tablespoon soy sauce
- 1 teaspoon liquid smoke
- 1 teaspoon maple syrup
- ¼ teaspoon salt
- ¼ teaspoon black pepper
- 1 hoagie roll
- 1 tablespoon butter
Cheese Sauce
- 2 ounces white American cheese
- 2 tablespoons milk
- 1 tablespoon butter
- 1 teaspoon Dijon mustard
- ¼ teaspoon garlic powder
Instructions
Philly Cheesesteak
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Preheat the oven to 400°F.
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Slice portobellos, onion, and pepper, then spread on a lined baking sheet.
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Drizzle with olive oil, soy sauce, liquid smoke, and maple syrup. Season with salt and pepper and toss to coat.
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Roast for 25–30 minutes, until vegetables are tender and slightly browned.
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Remove the veggies and turn the oven off. Butter the hoagie roll and place it in the still-hot oven for 3–5 minutes until toasted.
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Assemble by piling roasted veggies on the toasted hoagie and smothering with the cheese sauce (below).
Cheese Sauce
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In a small pot, combine the white American cheese, milk, butter, Dijon mustard, and garlic powder.
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Heat on the lowest setting and stir frequently until everything melts together into a smooth sauce.
Pro Tips
Video