Mushroom Fajitas

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This portobello mushroom fajita recipe is hearty and meatless, bursting with spicy Tex-Mex flavor! With colorful peppers, savory onions, and meaty slices of portobello mushrooms, these vegetarian fajitas are a nutritious and mouthwatering meal that’s sure to please.

overhead shot of a baking sheet with Portobello Mushroom Fajitas and flour tortillas arranged in the top right.


 

Vegetarian Fajitas Recipe

Fajitas are truly awesome. They just are, and that’s a fact. No one should resist the combination of sizzling peppers and onions, cooked to crisp-tender perfection with your favorite protein. And, while I’m definitely a fan of beef fajitas, chicken, and even shrimp fajitas, sometimes you need a good meatless entree. Enter easy portobello mushroom fajitas!

In this vegetarian fajita recipe, slices of portobello mushrooms take the place of meat, but trust me, even dedicated carnivores won’t miss it! Portobellos are known for their “meaty” texture and flavor, and when they’re sliced thinly, they’re just right for fajitas.

Also, the cooking method couldn’t be more simple: just season your veggie blend, arrange it on a sheet pan, and bake until tender. It’s a super-easy, uber-flavorful dinner that’s just perfect for busy families!

up close shot of sliced portobello mushrooms, sliced bell peppers, and sliced onions inside a glass bowl

Fajitas vs Tacos

Fajitas and tacos are similar, but there are a few key differences that you can use to tell them apart. Fajitas are made with palm-sized flour tortillas, usually topped simply with strips of grilled vegetables and meat, often steak.

Tacos, on the other hand, are can be made with corn or flour tortillas, and feature a filling of ground or chopped meat. Also, tacos usually don’t have cooked vegetables in them; instead, crisp raw veggies like tomato and lettuce are used as toppings. 

What You’ll Need

So, what ingredients will you need to make these quick, vegan, and vegetarian fajitas? I’m glad you asked! Here’s a quick rundown of each ingredient and some tips for easy substitutions.

  • Olive Oil: This is my go-to, but you could substitute avocado oil, or any other cooking oil that you prefer.
  • Lime Juice: A little acidity is so important in fajitas—it brings out the flavors in the seasoning mixture and in the vegetables. If you don’t have lime juice, use lemon juice, or you could substitute your favorite vinegar. (Keep in mind that some vinegars have a stronger fragrance and flavor than lemon or lime juice).
  • Homemade Fajitas Seasoning: You can use store-bought fajita seasoning, or make a quick batch of my amazing homemade fajitas seasoning!
  • Cayenne Pepper: Use this to taste, to add a spicy kick. If you don’t care for the heat of cayenne pepper, you can leave it out.
  • Portobello Mushrooms: You’ll want to get a few large portobello mushrooms, and slice them into ½-inch strips.
  • Bell Pepper: I like to use one each of red, green, and yellow bell peppers, but using just one color is totally fine. Slice the bell peppers thinly.
  • Yellow Onion: Red, white, or sweet onions are also fine. Slice thinly, just like the bell peppers.
  • Flour Tortillas: For serving. 
  • Optional Toppings: You can top the fajitas simply with a dollop of sour cream or go all out with avocado tomatillo salsa, avocado slices, chopped fresh cilantro, lime wedges, and any other toppings or garnishes that you like. 

How To Make Mushroom Fajitas

These delicious vegetarian fajitas require little prep and take very little time to put on the table. Slice your veggies, combine them with the seasoning mixture, and bake to perfection.

  1. Get Ready. Once your ingredients are assembled and ready to go, preheat your oven to 450˚F. Then, line a large baking sheet with foil. Set the baking sheet aside.
  2. Season Your Veggies. Get a large mixing bowl, and combine the olive oil, lime juice, fajitas seasoning, and cayenne pepper in it, giving it a good stir to mix. Add in your mushroom slices, peppers, and onions, and gently toss them to coat in the oil. Then transfer the veggies and mushrooms to your prepared baking sheet, and spread them out in a single layer.
  3. Bake, and Serve. Bake for about 15 minutes, or until the vegetables are tender. Take them out of the oven, and serve with flour tortillas and toppings of choice.
up close shot of portobello slices, pepper slices, and onion slices arranged on a gold colored baking sheet.

Recipe Tips

Before you start cooking, take a minute to look over these easy tips and tricks for making the perfect mushroom fajitas. This easy meal is so flexible, so be sure to put your own spin on it!

  • Extra Veggies: Not sure about portobello mushrooms? Feel free to substitute sliced button mushrooms or baby bellas – or go in a totally different direction, and use strips of zucchini, summer squash, eggplant… whatever you love!
  • Cheese: When it comes to tacos, burritos, and fajitas, you can’t really go wrong with cheese. For an extra-creamy twist, sprinkle shredded or crumbled feta, cotija, cheddar, Monterey jack, or pepper jack cheese over your fajitas.
  • Protein: This dish is wonderful as a meatless meal, but you could definitely add your favorite protein to it. Slices of guajillo steak, baked chicken, or sliced pork loin roast all work deliciously!

Serving Suggestions

If you’d like to add a side dish or two to the menu, some of my favorites to go with a plate of vegetarian fajitas include these vegetarian meatballs with a Southwestern orzo salad packed with corn, black beans, and creamy avocado.

Cornbread is good with just about anything, but I think it goes particularly well with Tex-Mex flavors. This light skillet cornbread is baked the old-fashioned way in a cast-iron skillet. Pair it with the fajitas and a bowl of my Minestrone soup for a full meal.

Parmesan potatoes with fajitas is one amazing combo! My kids love it! Also, try these lemon garlic roasted potatoes for a grain-free side that’s still hearty and filling.

overhead shot of a baking sheet with Portobello Mushroom Fajitas and flour tortillas arranged in the top right.

How to Store and Reheat Leftovers

To store, place your leftovers in airtight containers or food storage bags, and refrigerate. Properly stored, they’ll keep for 3 to 4 days or freeze for 1 month. Note that the frozen vegetables are likely to become soft and mushy once they’re thawed and reheated.

To reheat, place the desired portion in a covered skillet, over low heat. Heat until the veggies are sizzling and heated through, but don’t overcook, or they’ll become soft and mushy. You can also bake leftover portobello fajitas at 450˚F until hot. 

    wooden spoon stirring through Portobello Mushroom Fajitas in a baking sheet

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    5 from 15 votes

    Mushroom Fajitas

    With colorful peppers, savory onions, and meaty slices of portobello mushrooms, these vegetarian mushroom fajitas are a nutritious and mouthwatering meal that’s sure to please!
    Prep Time: 10 minutes
    Cook Time: 20 minutes
    Total Time: 30 minutes
    Servings: 4

    Ingredients 

    • 3 tablespoons olive oil
    • 3 tablespoons fresh lime juice
    • 2 tablespoons homemade fajitas seasoning
    • ¼ teaspoon cayenne pepper
    • 3 to 4 large portobello mushrooms, cut into ½-inch thick slices
    • 1 red bell pepper, sliced into strips
    • 1 green bell pepper, sliced into strips
    • 1 yellow bell pepper, sliced into strips
    • 1 yellow onion, thinly sliced
    • 8 low carb flour tortillas, for serving
    • lime wedges, for serving
    • salsa, for serving, optional
    • avocado slices, for serving, optional
    • chopped fresh cilantro, for serving, optional
    • sour cream, for serving, optional
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    Instructions 

    • Preheat the oven to 450˚F.
    • Line a large baking sheet with foil and set aside.
    • In a large mixing bowl combine olive oil, lime juice, fajitas seasoning, and cayenne pepper; mix until incorporated.
    • To the bowl add the mushroom slices, peppers, and onions; toss to combine.
    • Transfer the peppers and mushrooms to previously prepared baking sheet and arrange in one single layer.
    • Bake for 15 to 18 minutes, or until veggies are tender.
    • Remove from oven.
    • Serve with flour tortillas and optional fillings and toppings.

    Nutrition

    Serving: 2fajitas | Calories: 152kcal | Carbohydrates: 13g | Protein: 3g | Fat: 11g | Saturated Fat: 2g | Polyunsaturated Fat: 1g | Monounsaturated Fat: 8g | Trans Fat: 1g | Sodium: 124mg | Potassium: 463mg | Fiber: 4g | Sugar: 5g | Vitamin A: 1276IU | Vitamin C: 123mg | Calcium: 21mg | Iron: 1mg

    Nutritional info is an estimate and provided as courtesy. Values may vary according to the ingredients and tools used. Please use your preferred nutritional calculator for more detailed info.

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    23 Comments

    1. cathleensherin@gmail.com says:

      Made these fajitas last night with baby bellas (store was out of portobellos). SO GOOD! Just ate the leftovers for lunch and they were just as good (if not better) than last night. Thank you for sharing!

      1. Katerina Petrovska says:

        That’s great! I’m very glad you enjoyed it! Thank YOU! 🙂

    2. Catalina says:

      The best way to have a healthy dinner! Love how easy is to make it!

      1. Katerina Petrovska says:

        Thank you so much! I hope you’ll enjoy it! 🙂

    3. Sandra says:

      This deserves a spot on our weeknight rotation!! So good and amazing!

      1. Katerina Petrovska says:

        I hope everyone will enjoy it! Thank YOU! 🙂

    4. Amanda says:

      These are the best vegetarian fajitas! So much flavor!

      1. Katerina Petrovska says:

        Thank YOU! I hope you’ll enjoy it! 🙂

    5. Vikki says:

      So colorful and flavorful! These fajitas are great

      1. Katerina Petrovska says:

        Thank you so much! I hope you’ll enjoy it! 🙂

    6. Kristyn says:

      Mmmm!!! Hearty & packed with flavor!! What a great alternative to meat!

      1. Katerina Petrovska says:

        Thank YOU! I hope you’ll enjoy it! 🙂

    7. Juliane says:

      So much flavor I can SEEEE it!!

      1. Katerina Petrovska says:

        Thank YOU! I hope you’ll enjoy it! 🙂

    8. Beth says:

      What a great recipe! It’s perfect for vegetarians, and if you’re not vegetarian, you can add some meat to it, as well.

      1. Katerina Petrovska says:

        Thank you so much! I hope you’ll enjoy it! 🙂

    9. April says:

      Love this! Super tasty and a great addition to our rotation for meatless mondays!

      1. Katerina Petrovska says:

        Thank YOU! I hope you’ll enjoy it! 🙂

    10. Matt says:

      Such an amazing, tasty, sheet pan fajita recipe. I would have never have thought to swap out the chicken or beef with portobello mushrooms. Awesome!

      1. Katerina Petrovska says:

        Thank you so much! Please enjoy! 🙂