Combine meat, bread crumbs, onion, salt and pepper in medium bowl. Press into 8x8-inch square pan. Bake in preheated 375°F oven 18 minutes or until no longer pink in center; drain. Cut meat into quarters.
Place cheese over meat. Bake at 375°F 2 minutes or until cheese is melted. Place meat on bottom half of rolls; top with lettuce, tomato and top half of roll. Serve with mayonnaise, mustard and ketchup, if desired.