fajita veggies piled into charred corn tortillas with lime wedges next to it

Portobello Mushroom Vegetarian Fajitas

  • Author: Amy Estes
  • Prep Time: 10 minutes
  • Cook Time: 10 minutes
  • Total Time: 20 minutes
  • Yield: 4 people 1x


Incredible Vegetarian Fajitas! Perfectly seasoned, hearty portobello mushrooms, onions, and peppers on top of perfectly charred corn tortillas topped with fresh cilantro and lime juice. Vegetarian, gluten-free. Easy make-ahead meal, perfect meal prep recipe! Ready in under 30 minutes!



For the Fajitas

  • 2 tbsp olive oil
  • 2 large portobello mushroom caps (cleaned and sliced into strips)
  • 3 large bell peppers (sliced into strips) – I used a mix of red, yellow and green for color
  • 1/2 large red onion (sliced thin) – about 1 cup
  • 68 yellow corn or flour tortillas

For the fajita seasoning

  • 1 packet store-bought fajita or taco seasoning
  • 1/4 cup vegetable stock – low sodium
  • 1 tablespoon olive oil
  • 1 tablespoon chili paste (optional)

For Serving

  • Avocados sliced
  • Chopped fresh cilantro
  • Limes
  • Cojita cheese
  • Sour cream


Mix up the fajita sauce

  1. Add the fajita seasoning to a small bowl and combine with the vegetable stock and 1 tablespoon of olive oil, and 1 tablespoon chili pastes (if using) and whisk well. Set aside

Cook the mushrooms, onions and peppers

  1. Heat up a cast iron skillet to medium heat with 1 tablespoon olive oil.  Once hot, add the sliced mushrooms and cook for about 2-3 minutes until brown on both sides.  Once they are starting to brown, season the mushrooms with salt and pepper and set aside in a medium size bowl.
  2. In the same pan you cooked the mushrooms in, add more olive oil, heat the pan back to medium heat and add the sliced onions and peppers.  Season with salt and pepper and cook untl the veggies are softened and slightly brown and charred, turning them while they cook.  Place them in the bowl with the mushrooms. 
  3. Pour the fajita sauce all over the veggies and lightly toss to coat. 

Build the fajitas

  1. Char the tortialls over an open flame on the stove top or under the broiler for 1-2 minutes on a sheet pan in the oven. 
  2. Fill the tortillas with some of the fajita veggies, top with sliced avocado, cojita cheese, cilantro and a squeeze of lime juice. 


  • Clean the mushrooms easily by gently wiping them with a clean damp towel. Then slice them into strips that are about 1/4 inch thick.
  • Slice the onions and peppers thin to make it easier to cook them faster.
  • Add in other veggies like roasted cauliflower, broccoli, spinach, or tomatoes.
  • Add some protein. You can add in some cooked black beans, crispy tofu, chickpeas, or even some scrambled eggs.
  • Use store-bought fajita or taco seasoning or make your own by combing 1 tablespoon garlic powder, 1 tablespoon onion powder, 1 tablespoon ground cumin, 1 teaspoon oregano, and 1 teaspoon chili powder, and 1 teaspoon smoked paprika.
  • Mix up the toppings. Top these fajitas with salsa, guacamole, pico de Gallo, shredded carrots, shredded cheddar cheese, or even some adobo sauce for an extra spicy kick. 
  • Category: Main Dishes
  • Method: Sautéed
  • Cuisine: Mexican