01 - Preheat oven to 400°F. Lightly grease a baking dish.
02 - In a large bowl, toss the bell peppers and onion with olive oil, chili powder, paprika, cumin, garlic powder, onion powder, salt, and black pepper.
03 - Slice each chicken breast horizontally, but not all the way through, creating a large, thin piece (butterfly). Place between plastic wrap and pound to about 1/4-inch thickness.
04 - Evenly divide the vegetable mixture and cheese among the chicken cutlets. Lay the filling in the center.
05 - Roll up each chicken breast tightly and secure with toothpicks if needed.
06 - Place the roll ups seam-side down in the prepared baking dish.
07 - Sprinkle any remaining fajita seasoning over the top.
08 - Bake for 25–30 minutes, or until chicken is cooked through and the cheese is bubbling.
09 - Remove toothpicks, garnish with cilantro and serve with lime wedges and sour cream if desired.