Pound chicken pieces to flatten slightly. Coat well in bread crumbs. Arrange breasts around sides of 8 inch square glass dish. Cover with wax paper. Microwave on medium-high (70 per cent) 7 minutes or until juices run clear. Pour one-fourth of the spaghetti sauce over each portion. Place a slice of cheese on top of each. Cover dish, and microwave on meduium high 3 to 4 minutes, or until sauce is hot and cheese is melted.