Sheet-Pan Sweet Potato & Mushroom Fajitas with Guacamole

Directions

1. Heat two sheet pans

   Arrange racks in the upper and lower thirds of the oven and heat to 450°F with two heavy rimmed sheet pans inside. Preheating the metal starts browning the vegetables immediately and prevents a soft, steamed surface.

2. Season the sweet potato

   In a large bowl, toss the sweet potato with 1 tablespoon olive oil, 1 teaspoon cumin, 3/4 teaspoon smoked paprika, 1/2 teaspoon chili powder, 1/4 teaspoon oregano, 1/4 teaspoon salt and half the black pepper. Keep the sticks in a single layer so their edges caramelize.

3. Season the remaining vegetables

   In a second bowl, toss the mushrooms, red onion, bell pepper and dry corn with 1 1/2 tablespoons olive oil, the remaining cumin, smoked paprika, chili powder, oregano, 1/2 teaspoon salt and black pepper. Coating the vegetables separately prevents the sweet potato from breaking.

4. Start the sweet potato

   Carefully remove one hot pan with heat-safe mitts. Spread the sweet potato in one layer and roast on the lower rack for 10 minutes. Leave space around the pieces and return the pan to the oven promptly.

5. Roast the fajita vegetables

   Spread the mushroom mixture across the second hot pan. Roast both pans for 12 minutes, placing the mushrooms on the upper rack. Rotate the pans and turn the sweet potatoes, then roast for 6 to 8 minutes more, until the potatoes are tender with dark edges and the mushrooms are browned rather than watery.

6. Make the lime guacamole

   While the vegetables roast, mash the avocados with the juice of 1 lime, the grated garlic, chopped cilantro and remaining 1/2 teaspoon salt. Leave some small avocado pieces for texture. Press reusable wrap directly against the surface if it must wait longer than 10 minutes.

7. Brighten the roasted filling

   Combine the contents of both pans, drizzle with the remaining 1/2 tablespoon olive oil and squeeze over half of the second lime. Toss gently and taste. The filling should be smoky, well salted and bright enough to stand up to the tortillas.

8. Warm the tortillas safely

   Stack the tortillas, wrap them tightly in foil and warm in the switched-off oven for 5 minutes. Alternatively, warm each tortilla for about 20 seconds per side in a dry skillet until flexible; never place tortillas directly over an unattended gas flame.

9. Assemble the fajitas

   Spread guacamole in each warm tortilla, then add sweet potato, mushrooms, corn, bell pepper and red onion. Finish with cilantro leaves, jalapeño and pickled onions if using. Serve with the remaining lime wedges while the vegetables are hot.

Why this works

Swaps & notes

Easy swaps

• Use peeled butternut squash cut into 1/2-inch sticks instead of sweet potato; begin checking it after 20 total minutes.
• Replace cremini mushrooms with sliced portobello caps or oyster mushrooms, keeping the pieces broad enough to brown rather than shrivel.
• Corn tortillas make the meal gluten-free only when the package is certified gluten-free; warm them individually so they remain flexible.

Cook notes

• Mushrooms absorb rinse water. Wipe them clean and keep the slices fairly thick so they brown and remain visible in the finished fajitas.
• Frozen corn must be thawed and dried before roasting; wet kernels cool the pan and steam the surrounding vegetables.
• If only one sheet pan is available, roast the sweet potato first, transfer it to a plate and roast the remaining vegetables second rather than crowding everything together.

Storage

Cool the roasted vegetables promptly and refrigerate them separately from tortillas and guacamole within 2 hours for up to 4 days. Press wrap against the guacamole and use within 2 days. Reheat the filling on a sheet pan at 425°F for 8 to 10 minutes or in a skillet until steaming; warm tortillas separately. Freeze the roasted filling for up to 2 months, but do not freeze the guacamole.

Questions