Sheet Pan Portabello Mushroom Fajitas

Fajitas are always a crowd-pleasing dinner. Make them plant-forward by swapping in juicy, marinated portabello mushrooms for the meat! They’re cooked on a sheet pan with the peppers and onions to speed things up so these are weeknight-friendly.

Mexican food makes a frequent appearance in our household but fajitas always seem to be the forgotten meal. We love them, they’re simple, but we usually opt for the easier and equally delicious counterparts: tacos and burrito bowls.

For some reason it always seems so time-intensive to prepare the meat. So why not make them vegetarian?

Let me tell you about these mushroom fajitas. They are totally weeknight-friendly and bursting with flavor. Portabello mushrooms are drenched in an umami flavor bomb of soy sauce, red wine vinegar, garlic and crushed red pepper flakes before getting cooked until tender and perfect. A single sheet pan is all you need to cook everything so it couldn’t be simpler to throw these together.

Also, hello veggies! It’s such a feel-good meal.

Why mushrooms?

Mushrooms are a favorite ingredient in any plant-forward kitchen. They bring the umami component to a dish (which is typically missing when you cut back on meat). For fajitas, you also need something that has a similar shape to the more traditional strips of chicken or steak and portabellos work perfectly.

Benefits of sheet pan meals:

• Simple to prep ahead
• It makes cooking easier and faster
• Cleanup is a breeze, especially if you use parchment paper

Recommended fajita toppings

You can use whatever you like for toppings on these, but here are some of my favorites for mushroom fajitas:

• Pico de gallo
• Guacamole (or diced avocado)
• Fire-roasted corn (can buy frozen, or make yourself)
• Cilantro
• Limes
• Sour cream or plain Greek yogurt
• Shredded cheese

I also love how beautiful this meal is for entertaining. You can arrange everything on platters just like they do it in restaurants (steamy hot cast iron skillet optional!).

Be sure to offer plenty of accompaniments so each person gets to build their own and it’s a guaranteed hit. Now who wants one?

You might also like:

• Pizza Stuffed Portabello Mushrooms
• Shortcut Mushroom Ramen Bowls
• Tortellini Pasta Salad with Grilled Vegetables & Goat Cheese

Sheet Pan Portabello Mushroom Fajitas

These vegetarian portobello mushroom fajitas are bursting with flavor! The mushrooms are cooked on a sheet pan with the peppers and onions to speed things up so they’re a weeknight-friendly crowd-pleaser.

• Author: Leanne Ray, MS, RDN
• Prep Time: 20 minutes
• Cook Time: 20 minutes
• Total Time: 40 minutes
• Yield: 4 servings 1x
• Category: Mains
• Method: Oven
• Cuisine: Mexican
• Diet: Vegetarian

Ingredients

Scale 1x2x3x

• 1/4 cup soy sauce
• 2 Tbsp red wine vinegar
• 3 Tbsp neutral oil (like canola or grapeseed) – divided
• 1/2 tsp granulated garlic
• 1/2 tsp ground cumin
• 1/8 tsp crushed red pepper flakes
• 2 portabello mushroom caps
• 1 red bell pepper
• 1 red onion
• 8, 6 inch flour tortillas
• for serving: diced tomatoes, diced avocado, fire-roasted corn, shredded cheese, sour cream, cilantro, lime wedges 

Instructions

1. Preheat oven to 375 degrees. 
2. Prepare a sheet pan with nonstick cooking spray. 
3. Make the marinade by adding soy sauce, vinegar, 2 tablespoons of the oil and spices to a small jar. Cover tightly and shake until thoroughly combined. 
4. Prep portabello mushrooms: remove stems, clean out the gills with a spoon, and wipe the top of the cap clean with a damp towel. Cut into 1/2″ slices and add to a medium bowl, then pour the marinade over the top and toss to coat. Let sit at least 10 minutes. 
5. Meanwhile, slice bell pepper and red onion and add to sheet pan. Toss with the remaining tablespoon of oil and season with salt and pepper. Once mushrooms are done marinating, add to sheet pan. Transfer to oven and cook for 20 minutes. 
6. To assemble, add mushrooms, bell peppers and onions to a tortilla and add your favorite toppings.

Equipment

chef’s knife

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sheet pan

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Notes

• The equipment section above includes affiliate links to things I use often in my kitchen and recommend.
• Nutrition information was calculated for fajitas without toppings since this may vary.
• I love keeping frozen fire-roasted corn on hand. It’s available at many grocery stores now!

Nutrition

• Serving Size: 2 fajitas
• Calories: 313 calories
• Fat: 16 grams
• Carbohydrates: 35 grams
• Fiber: 4 grams
• Protein: 7 grams

Keywords: vegan fajitas, portabello mushrooms, vegan mexican recipes, sheet pan meals