Preheat your oven to 425°F and line a large sheet pan with parchment paper or aluminum foil for effortless cleanup afterward. This step takes just two minutes but saves serious time when dinner's done.

In a small bowl, whisk together chili powder, cumin, garlic powder, paprika, salt, and black pepper until thoroughly combined. You'll notice the spice blend becomes fragrant—this is your signal that everything is mixed perfectly.

Pat your chicken breast strips dry with paper towels, then toss them with 2 tbsp olive oil and half of the spice mixture in a large bowl. Don't skip the drying step because it's what allows the chicken to brown beautifully instead of steaming.

On your prepared sheet pan, arrange the marinated chicken strips in a single layer on one side, then spread sliced peppers and onions on the other half. Drizzle the vegetables with remaining 1 tbsp olive oil and remaining spice mixture, then toss gently to coat everything evenly.

Roast for 20-25 minutes until the chicken reaches 165°F internally and the vegetable edges turn golden brown and slightly charred—this is the sweet spot for cozy sheet pan fajitas summer recipe done right. Warning: if your pan is too crowded, vegetables will steam instead of roast, so don't overcrowd.

Remove from the oven and immediately squeeze fresh lime juice over the entire pan, stirring gently to distribute the brightness throughout. I always take a moment here to appreciate how good this smells—trust me on this one.

Warm your flour tortillas in a dry skillet for about 30 seconds per side, or wrap them in foil and place them in the warm oven for the last few minutes of cooking time. Warm tortillas make such a difference in texture and taste compared to cold ones.

Serve your warm summer dinner with warm tortillas, sour cream, fresh cilantro, and lime wedges so everyone can build their own personalized fajitas exactly how they like them.