Sprinkle salt and pepper over meat. In a skillet, cook meat in oil for 3-5 minutes on each side or until browned. Place meat and a slice of cheese on the bottom of the bun. Broil open-faced sandwich 4-6 in. from the heat for 2 minutes or until cheese is melted and bun is toasted. Spread mayonnaise over bun top. Place lettuce and tomato slices on cheese. Cover with bun top.