Potato Gratin

Potato au gratin sauce [reduced fat milk, water, cheddar cheese (pasteurized milk, cheese cultures, salt, enzymes, annatto for color), swiss cheese (part-skim milk, cheese cultures, salt, enzymes), unsalted butter (pasteurized cream, natural flavor, lactic acid, starter distillate), corn starch, salt, black pepper, nutmeg], potato [potato, citric acid (to preserve color)], swiss cheese (part-skim milk, cheese cultures, salt, enzymes).