Preheat your oven to 425°F and line a large sheet pan with parchment paper or foil for easy cleanup. While it heats, combine smoked paprika, cumin, chili powder, garlic powder, onion powder, and black pepper in a small bowl—this moment matters because dry spices bloom when they meet hot oil, releasing their essential oils instead of sitting dormant on cold chicken.

Pat your chicken strips completely dry with paper towels, then transfer to a large mixing bowl. Drizzle with olive oil and sprinkle the spice blend across the top, tossing until every piece wears a visible coating. I confess I used to skip this tossing step, thinking it didn't matter—it absolutely does, because uncoated spots cook differently than seasoned sections.

Arrange chicken strips on one half of your prepared sheet pan, leaving the other half empty for vegetables. Roast chicken alone for 12 minutes—this head start prevents vegetables from releasing water that steams the chicken instead of allowing it to caramelize, which is the whole point of using high heat.

While chicken roasts, slice your red and green bell peppers into half-inch strips and your yellow onion into similar thickness. Toss vegetables with a splash of olive oil and a pinch of salt. Why this timing? Adding vegetables now means they cook exactly long enough to soften without collapsing into mush.

Remove the pan from the oven after 12 minutes and arrange vegetable strips on the empty half, making sure they don't overlap the chicken. Return to the oven for another 16-18 minutes, until chicken reaches 165°F internally and pepper edges begin darkening at the corners. That beautiful caramelization signals your stunning sheet pan fajitas weeknight recipe hit the target.

While everything roasts, warm your corn tortillas wrapped in a damp kitchen towel in a 300°F oven or directly over a gas flame for 20 seconds per side if you have a burner. Warm tortillas stay pliable; cold ones crack when you fill them. This small gesture transforms the entire eating experience from functional to intentional.

Remove the sheet pan and let everything rest for 3 minutes—this allows juices to redistribute through the chicken so each bite stays juicy rather than drying out as you eat. Sprinkle cheese across the hot vegetables; residual heat melts it without requiring additional cooking.