each patty with one of the remaining patties sealing the edges firmly. Brown the patties in a large skillet over medium-high heat, turning once. Drain off the fat and pour the tomato sauce over the patties. Cover and simmer for about 15 minutes. Place a cheese slice on each patty, cover, and heat until the cheese is melted, about 2 minutes. Serve with the remaining sauce in the skillet poured over them.