Preheat the oven to 400 degrees.

Slice 4 bell peppers in half, and remove all seeds and the insides of the peppers.

Layer them in a single layer in the bottom of a greased baking dish.

Dice the cooked chicken.

In a large mixing bowl, combine 2 cups of the mozzarella cheese, the parmesan cheese, marinara sauce, diced chicken, garlic, red pepper flakes, as well as salt and pepper to taste.

Fill the inside of each pepper half with the chicken and cheese mixture.

Top the stuffed peppers with the remaining cup of mozzarella cheese.

Cover the baking dish with aluminum foil, and bake covered for 50 minutes.

Remove the aluminum foil, and broil the peppers for about a minute until the tops are browned.

Garnish with grated parmesan cheese and chopped parsley.