Dredge a chicken breast in the flour and shake off any excess. Then dip the chicken piece into the egg/milk mixture and then dredge in the Italian breadcrumb mixture. Shake off any of the excess breading and place to a baking dish. Repeat with the remaining chicken.
In a large skillet, pour your frying oil until it is 1/2 of an inch deep. Heat over medium heat. Once the oil is heated (sprinkle a tiny drop of water into the oil, if the drop sizzles it is heated, if the oil pops turn down the heat). Fry two breast at a time until golden brown on both sides. Place on paper towels to drain off excess oil.
In a large baking dish, brushed with a small amount of olive oil, pour 1 jar of marinara sauce and cover the bottom of the baking dish. Arrange chicken over the sauce, side by side making sure not to overlap. Sprinkle the Italian shredded cheese over the chicken. The cover with remaining jar of sauce. Bake in a 375 degree oven for 45 minutes or until your sauce is bubbly. Remove from oven and sprinkle your mozzarella cheese on top. Place back into the oven just enough for the cheese to melt and slightly brown.
Serve with your favorite pasta, bread sticks and salad.