01 - Preheat your oven to 375°F (190°C).
02 - Arrange the hollowed bell peppers upright in a baking dish.
03 - In a large bowl, combine the cooked chicken, rice, Alfredo sauce, 1 cup mozzarella, Parmesan cheese, garlic powder, Italian herbs, salt, and black pepper. Mix thoroughly until all components are well integrated.
04 - Spoon the prepared filling evenly into the hollowed bell peppers, ensuring they are generously filled but not excessively packed.
05 - Sprinkle the remaining 1/2 cup of mozzarella cheese over the tops of the stuffed peppers. Cover the baking dish loosely with aluminum foil and bake for 25 minutes.
06 - Remove the aluminum foil and continue baking for an additional 10 minutes, or until the cheese is fully melted and lightly golden, and the peppers have achieved a tender consistency.
07 - Remove from the oven. Garnish with fresh chopped parsley, if desired, and serve immediately.