Sheet Pan Roasted Vegetable Fajitas with Spiced Cauliflower
A vibrant sheet pan dinner featuring roasted bell peppers, onions, cauliflower, and portobello mushrooms tossed in smoky Mexican spices. The vegetables caramelize beautifully in the oven while you prepare fresh guacamole and warm refried beans. Perfect for busy weeknights when you want bold flavors without the fuss of stovetop cooking. Serve with warm tortillas for a satisfying meal that brings together tender roasted vegetables with creamy avocado and hearty beans.
Ingredients
- 1 white onion, thinly sliced
- 2 bell peppers, sliced
- 1 head cauliflower, chopped into small florets
- 1 portobello mushroom, chopped into bite-sized piecesbaby bella or cremini mushrooms1:1Smaller mushrooms work perfectlyjust slice thickly
5
- 2 tablespoons olive oil
- 1 tablespoon chili powder
- 1 teaspoon cumin
- 1 teaspoon smoked paprika, or regular
- 1 teaspoon garlic powder
- 1 teaspoon onion powder
- 1 teaspoon kosher salt
- ½ teaspoon kosher salt, additional for roasting
- 2 ripe avocados
- 1 lime, juiced
- ½ teaspoon kosher salt, for guacamole
- fresh cilantro
- 8 tortillas, flour or corn
- 1 15-ounce can vegetarian refried beans, or homemade
Instructions
- 1
Preheat the oven to 425 degrees Fahrenheit
- 2
Thinly slice the onion and bell peppers, chop the cauliflower into small florets, and chop the mushroom into bite-sized pieces
- 3
Toss the vegetables with olive oil and all spices in a large bowl
- 4
Line 2 baking sheets with parchment paper and spread vegetables in a single layer
- 5
Roast for 15 minutes, then remove sheets and stir the vegetables
- 6
Sprinkle additional salt over the vegetables and stir again
- 7
Return to oven and roast another 10 minutes until tender
- 8
Meanwhile, pit and mash the avocados with lime juice, salt, and cilantro
- 9
Heat the refried beans in a small saucepan
- 10
Char the tortillas over an open gas flame if desired until slightly blackened and warm
- 11
Serve vegetables and beans in tortillas topped with guacamole
Tips
Don't overcrowd the baking sheets - use two sheets to ensure proper roasting and caramelization of the vegetables.
Char tortillas directly over a gas flame for authentic flavor, or warm them in a dry skillet if no gas burner is available.
Good to Know
Store leftover roasted vegetables in the refrigerator for up to 3 days and reheat in a skillet or microwave.
Vegetables can be chopped and seasoned up to 4 hours ahead, then roasted when ready to serve.
Serve immediately while vegetables are warm with all toppings available for customization.
Common Mistakes
Don't skip the additional salt after the first 15 minutes of roasting to avoid underseasoned vegetables.
Avoid overcrowding the pan to prevent steaming instead of roasting.
Substitutions
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FAQ
Can I make these fajitas without oil?
Yes, you can roast the vegetables without oil by using vegetable broth or water to prevent sticking, though they won't caramelize as well.
What if I don't have smoked paprika?
Regular paprika works fine, or substitute with a pinch of chipotle powder for smokiness, though the flavor will be slightly different.
How long do the leftovers keep?
Roasted vegetables keep in the refrigerator for up to 3 days. Reheat in a skillet to restore some crispness before serving.