French Onion Chicken Casserole

boneless, skinless chicken breasts

or 2 teaspoons garlic powder

 teaspoon dried oregano

Red crushed chili pepper flakes, optional

Pinch of salt and fresh cracked pepper

 cup shredded mozzarella cheese (or Gruyere)

to 3 tablespoons unsalted butter

large onions, thinly sliced

 cloves garlic, minced

to 1/2 cup chicken broth

Fresh chopped parsley, for garnish