Make my crazy flavorful Vegetarian Fajitas with bell peppers, onions, meaty mushrooms and homemade fajita spice mix for a quick, family-friendly weeknight meal! Simply slice and season veggies, sear on a cast iron skillet til tender, and serve with guacamole, salsa, and refried beans + cheese for protein. A party in your mouth!

I'm a fajita gal through and through. The flavor ALWAYS delivers! My mom used to make them for dinner with that trusty fajita seasoning packet (you know) all the time growing up so they're super nostalgic, too.
I also have vivid memories of going to the local Mexican joint with the fam and ordering those skillet fajitas that come out all sizzling and magical. Nothin' beats my better-than-takeout skillet chicken fajitas, though!
And then if you were lucky enough to be there on your birthday like I was, they serenade you in sweet sombreros and serve you flan. We're living the fiesty life today with this unforgettable vegetarian fajitas recipe with mushrooms!
The low down on star ingredients
- Portobellos: Crave-worthy umami flavor for the star of our fajita show! When I was developing this recipe, I wanted the mushrooms to be the star and meaty portobellos do just that. Other recipes call for white mushrooms, but don't skip the portobellos--it was clear in testing that they're a dealbreaker!
- Peppers and onion: Colorful bell peppers to add flavor, texture, and a nutrient boost. I tested this recipe with all colors and also mini peppers and I can say with confidence that a mix of whatever colors you want works great.
- Spices: A zesty homemade seasoning mix of oregano, chili powder, garlic powder, and cumin for mega flavor. So much better than taco seasoning!
- Lime: Fresh lime juice to bring everything to life. When I first tested this recipe without it, it was missing that pop. The solution? Fresh like juice for sparkle! Don't skip it.
- Tortillas: I love these with pliable whole wheat flour tortillas to hold all the fillings but corn is a great gluten free option.
Let's make 'em!
- Slice all your veg and place in a large mixing bowl. Stir together spices in a small bowl. Add lime juice, oil and spices to veggies and toss.
- Get the veggies sizzling! We're cooking them for about 10 minutes.
- Pssst: a lot of homemade vegetarian fajitas recipes call for cooking the veggies for 5 minutes, resulting in really crisp peppers. What sets this recipe apart is that I cook my veggies a bit longer so they're more tender and flavorful. More char = more flavor. A big aha moment in recipe development!
- Warm tortillas. Divide veggies between tortillas and top liberally with toppings. Dig in!
The best fajita toppings
Ok ok ok. The fun is definitely in the toppings, so I'll give you the 411 on my favorites, in addition to the obvious cilantro and lime wedge combo.
- Guacamole: The salty, limey creamy notes just make the fajitas. This guac recipe is my absolute favorite. (Sometimes I use bottled lime juice, shhhh.) The coriander makes this guac unforgettable. When I tested this recipe without guac, they honestly weren't as satisfying.
- Salsa: I like the medium chunky kind. I always appreciate extra moisture in my fajitas, ya know?
- Cheese: Shredded cheddar or Monterey jack is the move.
- Hot sauce: I love Frank's or Tabasco Chipotle. Spice it up!
- Tortilla chips: Ok these are more on the side, but soooo good for crunch. We love the blue corn ones!
- Shredded lettuce or cilantro: We pretty much always have a salad on the side with dinner but I love me some crisp shredded lettuce. Cilantro adds herby goodness!
Storage tips
Store leftovers in the fridge for up to 4 days. Store all the veggie and topping components separately and simply reheat tortillas when you're ready to eat.
Please let me know if you love these fajitas by leaving a star rating and/or comment! I hope you adore them as much as I do!
Print30-Minute Skillet Vegetarian Fajitas with Portobellos
- Prep Time: 15 minutes
- Cook Time: 15 minutes
- Total Time: 30 minutes
- Yield: 4 servings
- Category: Main Meals
- Method: Stovetop
- Cuisine: Mexican
- Diet: Vegan
Description
Make my crazy flavorful Vegetarian Fajitas with bell peppers, onions, meaty mushrooms and homemade fajita spice mix for a family-friendly weeknight meal done in 30 minutes! Simply slice and season veggies, sear on a cast iron skillet til tender, and serve with guacamole, salsa, and refried beans + cheese for protein. A party in your mouth!
Ingredients
For the vegetables:
- 3 bell peppers, sliced
- 1 medium onion, sliced (reserve the other half for keeping guacamole green!*)
- 2 large portobello mushrooms, de-stemmed and gills removed (6oz)
- 2 tsp mild chili powder
- 1 tsp kosher salt
- 1 tsp oregano
- 1 tsp garlic powder
- 1 tsp cumin
- optional: ½ tsp smoked paprika
- Freshly ground black pepper
- 1 lime, juiced (2 tbsp)
- 2 tbsp extra virgin olive oil or avocado oil, plus more for cooking
For assembly and topping:
- 8 small corn or flour tortillas
- toppings: guacamole, pineapple salsa, freshly grated cheddar cheese, refried beans, hot sauce
Instructions
- Place sliced peppers, onions, and portobellos in a large mixing bowl. Add chili powder, salt, oregano, garlic powder, cumin, smoked paprika, and several grinds of black pepper to a small bowl. Stir to combine. Add lime juice, 1 tbsp of oil, and spices to vegetables and toss well with tongs to evenly coat.
- Heat a large cast iron skillet over medium high heat. Add a drizzle of oil. Once hot, add vegetables. Cook for about 10 minutes, stirring as needed but letting them sit on pan for a couple minutes at a time without stirring for a nice char.
- Warm tortillas either in the microwave or on the stove. Divide veggies between tortillas and top with your favorite toppings. My go-to is guacamole, salsa, cheddar cheese, and hot sauce. Crunchy tortilla chips on the side or refried beans for extra protein are also great!
Notes
- If you made guacamole, place leftovers in a small container and top with a thick round of raw onion. Anything under the onion will stay green!
Photos by The Nutritious Kitchen.
Ann says
Thank you for another delicious, nutritious, simple recipe! We had it tonight with Mexican rice. (chef's kiss*)
Alexis Joseph says
Wonderful, I’m so glad to hear! Thanks Ann!!
Val says
We made this for dinner last night and OMG it was insane! It's the first recipe in years that we were both still talking about the day after AND that we fought over leftovers for LOL. So incredibly flavorful and it literally took 2 mins to prepare! We followed it to a t, with store bought guac and salsa. Bill didn't miss meat at all - this is so satisfying as is!
I love so much all of the thought and consideration you put in to recipe development. Each recipe you create is so versatile - just like every other recipe on your site, this one is easy to prepare no matter what ingredients your readers have on hand, or what form of cooking they have access to. The best part of it all is, that no matter what, it ends up being a success each time! Loved this one and it's our new go-to for fajitas! (aka it's now a weekly meal lol)
Alexis Joseph says
You're the best, Val! I can't tell you how much your thoughtful comments mean to me. Store bought guac and salsa for the win. And heck yes for new weekly meal ideas! Love you girl 🙂
Maureen says
Love, love, LOVE this recipe. I doubled it and have been eating SO GOOD the past couple of days. The lime juice gives the veggies a great kick/taste. I'm already looking forward to making these again.
Alexis Joseph says
Yayyy thank you tons, Maureen! This is one of our go-to dinners 🙂
Elle says
Looks so yummy making next week!!
Rachael says
I’ve made this recipe several times now. I love it! So simple I don’t know why I never thought of it before but it’s going to be a regular for us.
Alexis says
YESSSS love it, Rachael!
Brea says
Wow- Yummy! these were a simple and delicious hit. I expect they'll be in our rotation.
Alexis says
I'm so glad! Thanks a ton for letting me know you loved these, Brea.
Aimee says
Delicious!! We built our tacos on flour tortillas with refried beans, the amazing fajita mixture, and topped with salsa. We will be making these again soon. Thank you for the yummy recipe!
Alexis says
Sounds so yummy!!
Claudine Seguin says
Delicious 😋
Made this and my 5 yo loved the portobello mushrooms. Thanks for the great recipe - once again!
Alexis says
Yayyy thanks so much for letting me know you loved the fajitas, Claudine!
Anna says
Delicious with all the toppings!! My whole fam loved
Alexis Joseph says
Yayyyy thank you a ton, Anna!
Dylan says
These are a staple for us! Such a fun, and quick, meal! Love the idea of grilling the veggies too!
Alexis Joseph says
Thanks so much, Dylan!!