The Easiest Sheet Pan Portobello Mushroom Fajitas Recipe

Looking for a delicious and healthy plant-based meal option? These portobello mushroom fajitas are easy to make and bursting with flavor. Give them a try today!
two quarter sheet pans with sliced portobello, red bell pepper and onions with two flower tortillas.

About this recipe

My Portobello mushroom fajitas recipe is one of my favorite recipes ever! This dish is vegan and bursting with flavor, making it perfect for a quick and nutritious dinner.

I promise you that the Portobello mushrooms give a meaty texture that even the most dedicated carnivores will love. I enjoy transforming these vegan fajitas into a sheet pan dinner with plant-based protein and a bowl of beans. It’s simple and makes a perfect meal for everyone to enjoy.

What do Portobello Mushrooms Taste Like? Portobello mushrooms have a rich, earthy flavor with a meaty texture, making them an excellent substitute for meat in vegetarian and vegan dishes.

When cooked, they develop a slightly nutty taste and absorb the flavors of the seasonings and marinades, making them incredibly versatile in various recipes.

two quarter sheet pans with sliced portobello, red bell pepper and onions


  • Portobello mushrooms: use different types of mushrooms if you prefer.
  • Bell peppers: You can make a really colorful dish by mixing red and yellow peppers.
  • Onions
  • Fajita seasoning
  • Olive oil and salt
two quarter sheet pans with sliced portobello, red bell pepper and onions and fajita seasonig

How to make Portobello fajitas

Simply slice the portobello mushrooms, bell peppers, and onions. Toss them with olive oil, salt, and fajita seasoning in a sheet pan.

Roast until the veggies are tender and slightly charred.

Assembling The Fajitas

  • Warm the tortillas: Heat your flour tortillas in a dry skillet or directly over a gas flame (my preferred way) until they are warm and slightly charred.
  • Layer the veggies: Place a generous amount of the cooked portobello mushroom mixture onto each tortilla.
  • Add toppings: Top with your favorite toppings, such as guacamole, fresh cilantro, a squeeze of lime juice, and even some black beans for extra protein.
  • Fold and enjoy: Fold the tortillas over the filling, and enjoy your delicious portobello mushroom fajitas!

Tips for the best fajitas

One of the best things about this portobello mushroom fajitas recipe is its versatility. Add more chili powder or a dash of cayenne pepper if you like your fajitas with some heat.

For those who prefer a milder flavor, reduce the amount of chili powder or omit it altogether. You can also serve spicy salsa or hot sauce on the side so that everyone can customize their own level of spiciness.

What to Serve with Portobello Fajitas

  • Guacamole: Creamy avocado goodness pairs perfectly with the fajitas.
  • Black beans: A protein-packed side that complements the flavors of the fajitas.
  • Mexican rice: Adds a bit of heartiness to the meal.
  • Tortilla chips and salsa: For some extra crunch.
  • Lime wedges: A squeeze of fresh lime juice brightens up the flavors.
Two sheet pans filled with roasted vegetables, including red bell peppers, red onions, and portobello mushrooms. The seasoned veggies are garnished with fresh cilantro. A slightly charred flour tortilla is placed in the top left corner, partially covering some vegetables—perfect for a fajitas recipe.

Sheet Pan Portobello Mushroom Fajitas

Alejandra Graf
Looking for a delicious and healthy plant-based meal option? These portobello mushroom fajitas are easy to make and bursting with flavor. Give them a try today!
5 de 2 votos
Prep Time 5 minutes
Cook Time 20 minutes
Total Time 25 minutes
Course Main Course
Cuisine Texan
Servings 2 people
Calories 218 kcal


  • Sheet pan


  • 4 large portobello mushrooms stems removed and sliced into strips
  • 1 red bell pepper sliced into strips
  • 1 large onion sliced into strips
  • 2 tablespoons olive oil
  • 1 tablespoon fajita seasoning *recipe in notes
  • Salt and pepper to taste

For Serving:


  • Set your oven to 400°F (200°C).
  • Slice the portobello mushrooms, bell peppers, and onions.
  • Toss the sliced veggies with olive oil, fajita seasoning, and salt in a large bowl
  • Arrange the seasoned veggies in a single layer on a sheet pan.
  • Place the sheet pan in the oven and bake for 20-25 minutes, or until the veggies are tender and slightly charred.
  • Remove from the oven and serve immediately with warm tortillas and your favorite toppings.


Fajita Seasoning
1 teaspoon dried oregano, 2 teaspoons cumin, 1 teaspoon garlic powder, 2 teaspoons chili powder. In a small bowl, combine the chili powder, ground cumin, paprika, garlic powder, dried oregano, 
How to prep portobello mushrooms?
  • Gently wipe the mushrooms with a damp cloth or paper towel to remove dirt. Avoid rinsing them underwater, as they can become waterlogged.
  • The stems of portobello mushrooms can be tough, so it’s best to remove them. Simply twist and pull them out or cut them off with a knife.
  • Slice the mushrooms into thick strips. This helps them retain their meaty texture when cooked.
How to store?
You can store the vegan fajitas in an airtight container in the refrigerator for 3-4 days. To reheat, gently warm the fajitas in a skillet over medium heat or in the microwave until heated through. If you plan to freeze them, store the fajitas in a freezer-safe container for up to 2-3 months. When ready to eat, thaw them in the refrigerator overnight and reheat as usual.
For ingredient substitutions in the Portobello mushroom fajitas recipe, you can consider using different types of mushrooms, such as shiitake or oyster mushrooms, if you prefer.
Additionally, if you want to add some extra protein, you could include tofu or tempeh along with or instead of the mushrooms. For those with dietary restrictions, you can use gluten-free tortillas or swap the lime juice for lemon juice if needed.


Serving: 1gCalories: 218kcalCarbohydrates: 20gProtein: 5gFat: 15gSaturated Fat: 2gPolyunsaturated Fat: 2gMonounsaturated Fat: 10gTrans Fat: 0.01gSodium: 22mgPotassium: 911mgFiber: 8gSugar: 9gVitamin A: 1990IUVitamin C: 80mgCalcium: 140mgIron: 4mg
Keyword how to prepare mushrooms, portobello


Nutritional information of this recipe is only an estimate, the accuracy for any recipe on this site is not guaranteed.

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Alejandra Graf
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