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 until evenly coated.
03 - Slice each chicken breast horizontally, cutting not all the way through, to butterfly and open like a book. Place between plastic wrap and pound to an even 1/4-inch thickness.
04 - Evenly divide the seasoned vegetable mixture and Monterey Jack cheese among the flattened chicken cutlets, laying the filling in the center of each.
05 - Tightly roll up each chicken breast and secure the edges with toothpicks to keep the filling intact.
06 - Place the assembled roll ups seam-side down in the prepared baking dish. Sprinkle any remaining fajita seasoning over the top.
07 - Bake for 25 to 30 minutes, or until the chicken is cooked through and the cheese is bubbling.
08 - Remove toothpicks, garnish with fresh cilantro, and serve alongside lime wedges and sour cream.