Vegan Portobello and Oyster Mushroom Fajitas

Whip up these quick vegan mushroom fajitas for a healthy, flavor-packed meal. A zesty homemade fajita marinade brings the authentic Mexican taste.

or read on for step-by-step instructions with photos

Hand holding a vegan mushroom fajita taco filled with portobello, oyster mushrooms, peppers, onions, and cilantro

What You’ll Need for This Mushroom Fajita Recipe

Ingredients

For the Vegan Fajita Marinade

  • 2 heaping tablespoons of canned chipotle

  • ½ teaspoon smoked paprika

  • 4 cloves garlic, peeled

  • 2 limes, zested and juiced

  • 1 orange, juiced

  • ½ cup extra virgin olive oil

  • ¼ cup apple cider vinegar

  • 1 tablespoon agave nectar

  • 1 tablespoon salt

For the Fajita Mushrooms and Veggies

  • 3 - 4 large portobello mushroom caps

  • 1 pound (454 g) oyster mushrooms, stems trimmed

  • 2 white onions, sliced

  • 8 mixed color peppers, sliced (I used manzano, poblano, and bell peppers)

Accompaniments for Serving Mushroom Fajitas

Equipment for Homemade Fajitas

  • Blender: To blend the marinade. Ingredients could also be chopped and whisked together if you don’t have a blender.

  • Knife & cutting board: To slice fajita vegetables.

  • Heavy-bottomed pan: Such as a cast-iron or stainless steel skillet.

Makes: 6 portions (2 tortillas each)

Prep: 10 min Cook: 20 min

A corn tortilla filled with vegan mushroom and pepper fajitas with fixings on top and in the background

How to Make Vegan Mushroom Fajitas
Step-by-Step with Photos

Step 1: Make the vegan fajita marinade

Combine the fajita marinade ingredients: chipotle, smoked paprika, garlic, lime zest & juice, orange juice, olive oil, apple cider vinegar, agave nectar, and salt in the jug of a blender, then blend until smooth.

Alternatively, chop the chipotle and garlic, then whisk the ingredients together.

If you’ve got more than 30 minutes, let the mushrooms marinate for at least an hour—or even overnight. They act like little sponges, soaking up tons of flavor. If you’re short on time, no worries—this marinade still packs a serious punch quickly.

Vegan fajita marinade in a blender

Step 2: Prep and cook the fajita mushrooms and veggies

Slice the onions and peppers, but keep the mushrooms whole for now. Sear the veggies and mushrooms separately in a very hot pan for a few minutes each, until tender and slightly charred.

After searing, slice the mushrooms and toss everything together in a bowl or tray with the marinade.

Before serving, quickly reheat the mixture in the same pan on the stove.

Prefer hands-off cooking? See the sheet pan oven method in the substitutions section below.

Fajita mushrooms, onions, and peppers in an aluminum pan covered with homemade vegan fajita marinade

Step 3: Warm tortillas and serve the fajitas

Warm tortillas on the stove, in an oven, or microwave. Serve fajitas alongside the warmed tortillas and your favorite garnishes.

I served mine with homemade pinto bean spread, pico de gallo salsa, fresh avocado, shredded cabbage, cilantro, and lime wedges. It was quite a colorful spread!

Tablescape of vegan fajitas with fixings and tortillas

My Tips for the Best Mushroom Fajitas

  • Use a heavy pan: A cast-iron or heavy stainless steel pan holds heat well, helping you sear and caramelize the fajita veggies properly. Lightweight non-stick pans just don’t get hot enough to build that deep golden-brown color without overcooking the veggies.

  • Don’t overcrowd the pan: Give your mushrooms and vegetables space. If the pan’s too full, they’ll steam instead of sear, and you’ll miss out on all that deep, roasted flavor.

  • Crank the heat: Fajitas are all about quick, high-heat cooking. That’s what keeps the veggies tender, juicy, and just the right amount of crisp. Use high heat whether you're cooking on the stovetop or roasting in the oven.

  • Get creative with leftovers: Leftover fajita mushrooms and veggies are great in omelets, wraps, burritos, or taco bowls with rice or quinoa.

  • Pair it with a drink: Round out your meal with a classic margarita, mezcal cocktail, or an ice-cold Mexican beer. For a non-alcoholic option, try sangrita, a fruit agua fresca, or chilled hibiscus tea (jamaica).

Mushroom Fajita Substitutions

  • Fajita oven method: Slice the onions, peppers, and mushrooms, toss them with the marinade on a sheet pan, and roast at 450°F for 15–20 minutes, flipping halfway through, until tender and lightly charred.

  • Fajita marinade: In a pinch, skip the homemade marinade and mix store-bought taco seasoning with lime juice and olive oil. No taco seasoning? Use a quick blend of chili powder, cumin, and garlic powder.

  • Mushrooms: The best mushrooms for fajitas are thick and meaty, like oyster or portobello. Other great options include cremini, button, or shiitake mushrooms.

  • Peppers: Any sweet or mild pepper will work here—try Anaheim, cubanelle, or banana peppers for a twist.

  • Agave nectar: Swap it with honey, maple syrup, or even plain sugar if needed.

  • Chipotle: Use other hot chiles like serrano, jalapeño, or habanero. For smoky heat without the prep, chipotle powder is a great stand-in.

How to Store Leftover Mushroom Fajitas

  • Fridge: Store leftover mushroom fajitas in an airtight container in the fridge for up to 5 days. Let everything cool completely before sealing to avoid excess moisture.

  • To Reheat: Warm leftovers in a hot pan over medium heat for a few minutes until heated through. This helps revive the sear and keeps the veggies from going soggy. The microwave works too, but the texture will be softer.

  • Freezer: You can freeze cooked mushroom fajitas for up to 3 months. Keep in mind the veggies will soften once thawed, but the flavor will still hold up. Freeze tortillas separately, wrapped tightly in foil or a freezer-safe bag.

Fresh corn tortillas being weighed at the tortilleria for serving with vegan fajitas at home

That’s it—dig into your flavorful mushroom fajitas!

After living in Mexico for over a year, we came to love fresh corn tortillas. We’d buy them by the kilo from a tiny tortilleria run by four women pressing and cooking tortillas on a hot comal (pictured above). If you can find something similar near you, grab them!

If not, flour tortillas or even lettuce wraps work just as well. However you serve them, these vegan mushroom fajitas are easy to make, packed with flavor, and even better as leftovers.


Pin this Mushroom Fajitas Recipe for Later!

Vegan portobello and oyster mushroom fajitas with homemade marinade on a table with pico de gallo, pinto bean spread, cilantro, avocado, cabbage, and tortillas

Vegan Mushroom Fajitas Recipe

These portobello and oyster mushroom fajitas are quick, easy, and perfect for meal prep. Enjoy flavorful leftovers all week long!

Makes: 6 portions (2 tortillas each)   

Prep: 10 min   Cook: 20 min

Dietary Notes: Gluten-free, Dairy-free, Egg-free, Vegan, Vegetarian, Low-carb

Mushroom Fajita Ingredients

For the Vegan Fajita Marinade

  • 2 heaping tablespoons of canned chipotle

  • ½ teaspoon smoked paprika

  • 4 cloves garlic, peeled

  • 2 limes, zested and juiced

  • 1 orange, juiced

  • ½ cup extra virgin olive oil

  • ¼ cup apple cider vinegar

  • 1 tablespoon agave nectar

  • 1 tablespoon salt

For the Fajita Mushrooms and Veggies

  • 3 - 4 large portobello mushroom caps

  • 1 pound (454 g) oyster mushrooms, stems trimmed

  • 2 white onions, sliced

  • 8 mixed color peppers, sliced (I used manzano, poblano, and bell peppers)

Accompaniments for Serving Mushroom Fajitas

How to Make Mushroom Fajitas

  1. Make the fajita marinade. Blend chipotle, smoked paprika, garlic, lime zest and juice, orange juice, olive oil, vinegar, agave, and salt until smooth. Alternatively, finely chop the chipotle and garlic and whisk everything together.

    Marinate the mushrooms (optional). If time allows, marinate whole mushrooms for 1 hour or overnight. If not, you’ll add the marinade after cooking.

  2. Prep and cook the fajita veggies. Slice onions and peppers; keep mushrooms whole. Sear each veggie separately in a very hot pan until lightly charred. Slice mushrooms after cooking. Toss everything with the marinade in a bowl, then reheat briefly in the same pan before serving.

    Sheet pan method (optional). Slice and toss mushrooms, onions, and peppers with marinade on a sheet pan. Roast at 450°F for 15–20 minutes, flipping halfway through.

  3. Warm and serve. Heat tortillas on the stove, in the oven, or microwave. Serve the mushroom fajitas with your favorite toppings like avocado, pinto bean spread, pico de gallo, shredded cabbage, and lime.

Top Tips for the Best Mushroom Fajitas

  • Use a heavy pan: Cast iron or stainless steel gives you the sear you need—non-stick pans won’t get hot enough.

  • Don’t crowd the pan: Cook in batches so the veggies sear, not steam.

  • Use high heat: Quick, hot cooking keeps everything tender, juicy, and just the right amount of crisp without overcooking.

Did you try this mushroom fajitas recipe? 

I’d love to hear how it went—or how you made them your own! Leave a comment below, or tag me on Instagram @onecreativecook if you share your creation.

More Vegan Recipes to Try Next

One Creative Cook

Hi, I’m Reem!

I’m a chef turned full-time traveler, sharing my tried-and-true recipes. With 15+ years of professional experience and plenty of time cooking on the road, you’ll find restaurant-quality recipes adapted for any kitchen setup or skill level!

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