Vegetarian portobello mushroom fajitas are a simple and crowd-pleasing dinner! They’re cooked on a sheet pan with the peppers and onions to speed things up and make clean-up a breeze. Great for a weeknight!
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 portobello mushroom fajitas. They are totally weeknight-friendly and bursting with flavor from the marinade. Portobello 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’s a really low maintenance recipe.
Also, hello veggies! This is such a feel-good meal.
Marinade for Portobello Mushrooms
The first step in this recipe is to create a big-flavor marinade and let the mushrooms soak for a bit. Here’s what goes in:
- soy sauce
- red wine vinegar
- neutral oil (like canola or grapeseed)
- granulated garlic
- ground cumin
- crushed red pepper flakes
Why mushrooms?
Mushrooms are a favorite ingredient in any plant-forward kitchen. They bring the umami component to a dish (which can sometimes go missing when you cut out meat).
For fajitas, you also need something that has a similar shape to the more traditional strips of chicken or steak and portobellos work perfectly. They also have a “meaty” texture.
Recommended Toppings for Portobello Mushroom Fajitas
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 & shredded cheese (unless you want to keep them vegan of course!)
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 favorite. Now who wants one?
More mushroom recipes:
- Pizza Stuffed Portabello Mushrooms
- Shortcut Mushroom Ramen Bowls
- Tortellini Pasta Salad with Grilled Vegetables & Goat Cheese
Sheet Pan Portabello Mushroom Fajitas
Vegetarian portobello mushroom fajitas are a simple and crowd-pleasing dinner! They’re cooked on a sheet pan with the peppers and onions to speed things up and make clean-up a breeze. Great for a weeknight!
- Prep Time: 20 minutes
- Cook Time: 20 minutes
- Total Time: 40 minutes
- Yield: 4 servings
- Category: Mains
- Method: Oven
- Cuisine: Mexican
- Diet: Vegetarian
Ingredients
- 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 portobello 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
- Preheat oven to 375 degrees.
- Prepare a sheet pan with nonstick cooking spray.
- 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.
- Prep portobello 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.
- 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.
- To assemble, add mushrooms, bell peppers and onions to a tortilla and add your favorite toppings.
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.
Want More Plant-Forward Recipes?
Join my VIP list and I'll send you five reader favorites! Healthy, flavor-packed recipes. What's not to love about that?
Toni says
Hi Leanne! I met you while I was an intern at Tri-County Health Dept from 2015-16. I believe you were working on a healthy bev initiative at the time (?). Your recipe looks great, can’t want to try it! Congrats on your blog, I’ll take some time to look through it soon.
Leanne says
Hi Toni, I remember you! Thanks for the sweet compliment. I hope you are doing well!