Close up of mushroom philly cheeseteak with provolone cheese
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Vegetarian Mushroom Cheesesteak with Caramelized Onions

This vegetarian Philly cheesesteak is full of sauteed mushrooms and peppers and topped with sweet caramelized onions on a sub roll. 
Prep Time10 mins
Cook Time30 mins
Total Time40 mins
Course: Main Course
Cuisine: Vegetarian
Servings: 4 subs
Calories: 414kcal
Author: Cassidy Reeser, RDN, LDN


  • 16 ounces Baby bella or white mushrooms, thickly sliced
  • 2 tablespoons olive oil, divided
  • 1 tablespoon soy sauce
  • 1 tablespoon all-purpose flour
  • 1 teaspoon dry oregano
  • 1 red bell pepper, sliced
  • 1 green bell pepper, sliced
  • 2 large onions white, yellow, and red all work
  • 1/2 teaspoon salt
  • 4 6" sub rolls
  • 4 slices provolone cheese


  • To make the caramelized onions: In a large skillet, heat 1 tablespoon olive oil over medium heat. Saute the sliced onions for 10 minutes, until lightly browned. Sprinkle with 1/2 teaspoon salt and lower the heat to medium low. Stir the onions every 7-10 minutes. They're ready when golden brown and sweet.
  • In a medium skillet, heat 1 tablespoon of olive oil over medium heat. Saute the mushrooms and peppers until the mushroom release most of their juices, about 7-8 minutes. 
  • Sprinkle mushrooms with soy sauce and oregano. To thicken the mushrooms and their juices, sprinkle with 1 tablespoon of flour, stirring to brown. 
  • Melt the provolone cheese by placing each slice over a section of mushrooms and peppers. Cover the pan with a lid to melt.
  • Scoop the melted cheese and mushrooms onto a toasted sub roll. Top with caramelized onions and enjoy!


Serving: 1mushroom cheesesteak | Calories: 414kcal | Carbohydrates: 49g | Protein: 18g | Fat: 17g | Saturated Fat: 5g | Cholesterol: 19mg | Sodium: 1090mg | Potassium: 633mg | Fiber: 4g | Sugar: 11g | Vitamin A: 1290IU | Vitamin C: 69.9mg | Calcium: 250mg | Iron: 12.1mg