1 pound cheese, sliced 1 1/2 inches
1 thick slice white Cheddar cheese
1 1/2 cups mayonnaise
1 cup ketchup
Preheat oven to 350 degrees F (175 degrees C). Spread 1/2 cup of the sliced cheese on two baking sheets. Place the au gratin mixture over the cheese, saran or nonfat cooking spray, brush middle and sides of pans with ketchup.
Bake in preheated oven for 20 to 25 minutes, uncovered.