These portobello mushroom fajitas deliver incredible smoky flavor and satisfying texture in just 30 minutes. Using large portobello caps creates a meaty, substantial filling that even dedicated carnivores will love. They are perfect for a quick weeknight dinner or a fun, interactive gathering with friends.

I first fell for the magic of mushrooms during a trip through Oaxaca, where their earthy depth was celebrated in every local market. This recipe captures that spirit, transforming humble ingredients into a vibrant, celebratory meal. I love serving these fajitas for casual dinners alongside other favorites, like my easy sheet pan quesadillas, creating a true fiesta. The rich, savory notes of the portobello pair wonderfully with the smoky spice of my homemade chicken enchiladas, making for a fantastic Tex-Mex inspired spread.

What You’ll Need for Perfect Portobello Mushroom Fajitas

Be sure to see the recipe card below for the full listing of ingredients, instructions, notes, and estimated nutritional information.

Portobello Mushroom Fajitas

Easy 30-minute portobello mushroom fajitas with smoky marinade! Tender mushrooms, peppers, and onions in warm tortillas. Perfect vegetarian weeknight dinner option.

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Prep Time 15 minutes mins

Cook Time 15 minutes mins

Total Time 30 minutes mins

Course Dinner

Cuisine Mexican-Inspired

Servings 4 servings

Calories 280 kcal

Equipment

• small bowl
• large bowl
• whisk
• spoon
• large skillet or cast-iron pan
• knife
• cutting board
• measuring spoons

Ingredients

  

Marinade

• 2 tablespoons olive oil
• 2 tablespoons fresh lime juice
• 1 teaspoon chili powder
• 1/2 teaspoon ground cumin
• 1/2 teaspoon smoked paprika
• 1/4 teaspoon garlic powder

Fajitas

• 3 large portobello mushroom caps stems and gills removed
• 1 large yellow onion sliced into 1/2-inch strips
• 1 large red bell pepper sliced into 1/2-inch strips
• 1 large green bell pepper sliced into 1/2-inch strips
• 8 medium flour tortillas
• sour cream for serving
• fresh cilantro chopped, for serving

Instructions

 

• In a small bowl, whisk together 2 tablespoons of olive oil, 2 tablespoons of lime juice, 1 teaspoon of chili powder, 1/2 teaspoon of cumin, 1/2 teaspoon of smoked paprika, and 1/4 teaspoon of garlic powder to create the marinade.
• Carefully scrape out the dark gills from the underside of 3 portobello mushroom caps using a spoon, then slice the caps into 1/2-inch thick strips. Place the strips in a large bowl.
• Pour the marinade over the mushroom strips and toss gently until they are evenly coated. Let them marinate for 10 minutes at room temperature.
• While the mushrooms marinate, heat a large skillet or cast-iron pan over medium-high heat. Add the sliced onion and bell peppers and cook for 6-8 minutes, stirring occasionally, until the vegetables are softened and have some charred spots. Transfer the vegetables to a plate.
• Add the marinated mushrooms to the same hot skillet. Cook for 5-7 minutes, without moving them too much, until they are deeply browned and tender.
• Return the cooked peppers and onions to the skillet with the mushrooms and toss everything together to combine and heat through, about 1 minute.
• Warm 8 flour tortillas by heating them in a dry skillet for 30 seconds per side or wrapping them in a damp paper towel and microwaving for 30 seconds until pliable.
• Serve the fajita mixture immediately with the warm tortillas, along with sour cream and fresh cilantro for topping.

Notes

Let mushrooms marinate for 10 minutes at room temperature for best flavor.

Keyword portobello mushroom fajitas, quick dinner, vegetarian

Ways to Customize This Recipe

• Make It Cheesier: Add crumbled queso fresco or a sprinkle of cotija cheese before serving.
• Add More Protein: Stir in a can of black beans with the vegetables for extra heartiness.
• Spicy Version: Include a diced jalapeño with the peppers or add a dash of hot sauce to the marinade.

My Pro Tips for Perfect Results

• Prep the Mushrooms: Take a moment to scrape out the dark gills for a nicer appearance and less muddy color.
• Get a Good Sear: Let the mushrooms cook undisturbed in the hot skillet to develop deep, flavorful browning.
• Char the Veggies: Don’t stir the peppers and onions too often so they get those desirable charred spots.
• Warm Your Tortillas: This simple step, similar to the technique for my chicken shawarma, makes them soft and pliable.

How to Store and Reheat Your Fajitas

• Store: Keep the fajita filling in an airtight container in the refrigerator for up to 4 days.
• Freeze: Freeze the cooled vegetable mixture in a freezer-safe bag for up to 3 months.
• Reheat: Warm the filling in a skillet over medium heat or in the microwave until heated through.
• Make-Ahead Tip: The marinade can be whisked together a day ahead, and the vegetables can be sliced and stored separately.

Frequently Asked Questions

More Mexican-Inspired Favorites

• Easy Chicken Tacos
• Vegan Thai Red Curry
• Shrimp Burrata Spaghetti
• Black Pepper Chicken

Why This Fajita Recipe Is a Weeknight Hero

With its robust flavor and quick preparation, these portobello mushroom fajitas are a guaranteed hit for any busy evening. The combination of savory mushrooms and sweet peppers creates a truly satisfying meal. I hope this recipe becomes a cherished favorite in your home, just as it is in mine.