Vegetarian Sheet Pan Fajitas with Black Beans

If you’ve ever wondered how to make mouthwatering meatless fajitas… or if you can make fajitas in the oven…the resounding answer is YES!

Yes, and yes, and they’re delicious, easy to make, and take weeknight dinners from meh to WOW in minutes. Even meat-eaters will devour these fajitas without missing a beat thanks to meaty mushrooms and hearty black beans.

What are Fajitas?

Have you ever sat at a restaurant and out comes a sizzling platter of veggies? Well, that’s fajitas!

Fajitas are a popular Tex-Mex dish that’s comprised of thinly sliced meats – often chicken or steak – along with thin strips of onion and bell peppers. The filling is served in warm tortillas with common taco condiments such as salsa, sour cream, and diced tomatoes.

Ingredients for Vegetarian Fajitas

Fajita veggies include onion and bell peppers, plus the addition of thinly sliced meat of choice. In this vegetarian version, we’re keepin’ the veggies and adding some plant-based texture and protein.

• Onion: I like to use red onion because it adds a beautiful color and is quite delicious when roasted. You can absolutely substitute with yellow or white onion if it’s what you have.
• Bell Peppers: again, hello, color! Use any combination of red, yellow, orange, and green peppers. I like to throw a green one in because it has a little more of a peppery flavor than the sweeter red, yellow, and orange varieties.
• Portobello Mushrooms: use these mushroom caps for the best “meat-like” substitute in these fajitas. You can easily slice the large caps into thin strips. If you can’t find caps, feel free to slice up button mushrooms.
• Black Beans: it’s important to have some protein in veggie fajitas to keep you full and satisfied, and black beans definitely do the trick. Plus, they’re delicious!
• Fajita Seasoning: of course we’re using a homemade seasoning blend! This one is super easy to throw together and store in the pantry for those weeknight dinners. It’s a mildly spicy blend of cumin, chili powder, garlic and onion powder, dried oregano, and more.

How to Make Sheet Pan Fajitas

To make oven-baked fajitas, you’ll need a large sheet pan. I recommend using the biggest one you have. If you have a half-sheet pan or jelly roll pan, use it. The more space the veggies have to roast in the oven, the better.

Thinly slice the onion, peppers, and mushrooms. Once they’re prepped, toss them in a little bit of oil. I like to use olive oil, because it’s what I usually cook with, but any neutral oil will work for this purpose. I also spread a little oil on the pan before I add the veggies. This encourages a nice roast and caramelization on the veggies while they are in the oven.

Before they go into the oven, they get a nice toss with the spice mix. Use your clean hands to toss it all together and make sure all those strips of goodness are covered.

Then, it’s time to bake! Place the baking sheet in the oven and bake the vegetables for about 10 minutes. Then, add the black beans to the sheet pan and toss to combine them with the veggies.

Place it back into the oven, this time on broil, to encourage some of the classic char you’ll find in fajitas. Carefully watch them at this point to make sure they don’t burn.

With the veggies tender and caramelized, it’s time to dig in!

Assembly & Toppings

Fajita veggies and black beans are essentially taco filling, so to assemble them, start with a tortilla. Use whichever you prefer between corn or flour tortillas. If using corn, fry the tortillas in a tiny bit of oil to warm them so they don’t break.

Add the veggies and bean mixture to the tortilla, and top with your favorite taco toppings! Here are some ideas:

• Chopped cilantro and a squeeze of fresh lime are my must-dos!
• Salsa or Pico de Gallo
• Sour Cream
• Guacamole, diced avocado, or avocado sauce
• Shredded cheese or cotija crumbles
• And you know I’ve got to say SAUCES! If you like it spicy, you’ve got to try jalapeno sauce. For a milder sauce, try a creamy cilantro lime. For some smokiness, drizzle on chipotle sauce. Or, to simply amp up the flavor, drizzle on extra fajita sauce.

You can also add the fajita veggies to a bowl and make a fajita bowl – similar to a burrito bowl – instead!

Depending on the toppings you choose, this recipe is vegan (with dairy-free toppings), gluten-free (with corn tortillas), and vegetarian with them all!

Serving Ideas

Taco night is the best because all of my favorite things can come together on one table (and who can argue with a sheet pan meal?!)

Of course, I love to start with a queso dip appetizer served with tortilla chips. But as far as sides go, Cheesy Mexican Rice or Cilantro Lime Rice are great options. Elote Corn Dip can be enjoyed as a side salad, too, or throw on some sweet corn salsa.

Storage & Make Ahead Options

If you have leftover black bean fajitas or want to make them ahead for meal prep, let them cool and store them in an airtight container in the fridge for up to 4 days. To make meal prep easier, divide them into individual servings.

Reheat the veggies in the microwave, or in the oven (or even on the stovetop) until heated through. Then, proceed with assembling your fajita as desired.

Did you make this recipe? Please leave a star rating and review in the form below. I appreciate your feedback, and it helps others, too!