01 - Preheat oven to 400°F. Lightly grease a large baking dish with 1 tablespoon of olive oil, coating the bottom and sides evenly.
02 - Arrange the sliced red, yellow, and green bell peppers along with the red onion in an even layer across the bottom of the prepared baking dish. Drizzle with the remaining olive oil, then sprinkle with half of the salt, black pepper, Italian seasoning, and smoked paprika. Toss the vegetables gently to coat evenly.
03 - Pat the chicken breasts dry with paper towels. Season both sides of each breast with the remaining salt, black pepper, Italian seasoning, and smoked paprika, pressing the spices gently into the meat.
04 - Place the seasoned chicken breasts on top of the vegetable bed in the baking dish. Scatter the minced garlic evenly over the chicken and vegetables.
05 - Cover the baking dish tightly with aluminum foil and bake for 20 minutes, allowing the chicken to cook through while the vegetables steam beneath.
06 - Remove the foil and sprinkle the mozzarella and Parmesan cheeses evenly over each chicken breast. Return the dish to the oven uncovered and bake for an additional 10 minutes, or until the chicken registers 165°F internally and the cheese is melted and golden.
07 - Remove from the oven and let the dish rest for 5 minutes before serving to allow the juices to redistribute. Serve the chicken alongside the roasted peppers and onions.