Preheat your oven to 425°F (220°C). Line a large baking sheet with parchment paper or foil for easy cleanup.
Place the sliced chicken, bell peppers, and onions on the sheet pan. Drizzle with olive oil and sprinkle with all the seasonings. Toss everything together directly on the pan until well coated.
Spread the ingredients out into an even layer. Roast in the preheated oven for 20–22 minutes, or until the chicken is fully cooked and the vegetables are tender with slightly charred edges.
Squeeze fresh lime juice over the fajitas straight from the oven. Serve hot with warm tortillas and your favorite toppings.