Preheat oven to 400°F. Set aside a large baking sheet.
Cut the chicken into 1/2-inch wide strips. Cut bell peppers and onions into thin slices.
Scatter the chicken, bell peppers, and onions evenly across the baking sheet. Sprinkle cumin, chili powder, garlic, paprika, salt and pepper on top and drizzle with oil.
Toss all ingredients on the pan to coat evenly using two spoons.
Bake for about 15 minutes in the oven or until the chicken is cooked through .
Remove from oven, stir chicken and vegetables. Then slide them one-quarter of the way over, to make space for tortillas.
Mop up excess juices with a paper towel, and then add the tortillas to the pan. Return to the oven and bake for 5 more minutes.
Remove from oven and squeeze optional fresh lime on top. Serve in tortillas with optional toppings like sour cream and avocado.