Preheat oven to 375°F and line a baking sheet with parchment paper.
In a shallow bowl, combine bread crumbs, flour, and parmesan cheese. In a separate bowl, beat the eggs.
Dip each chicken breast into the egg mixture, then into the bread crumb mixture. Place the chicken on the prepared baking sheet and bake for 20 minutes or until the chicken is cooked through.
Heat the olive oil in a large skillet over medium heat. Add the butter, onions, and garlic. Cook for 3 minutes or until the onions are softened.
Stir in the tomato sauce, oregano, and red pepper flakes and cook for 5 minutes.
Place a slice of mozzarella cheese on each chicken breast and top with the tomato sauce. Place the buns on the baking sheet and bake for 5 minutes or until the cheese is melted.
Assemble the burgers with the chicken, tomato sauce, and buns. Serve warm.
Interesting Facts
Parmesan cheese is an Italian cheese made from cow's milk.
Parmesan cheese has a nutty, salty flavor.
Tomato sauce is a popular condiment made from tomatoes, onions, and herbs.
Mozzarella cheese is a soft, white cheese made from cow's milk.
Hamburger buns are a type of bread commonly used for burgers.