Grease a shallow 13x9-in. baking dish with the butter; set aside. In a small saucepan, combine the cream, milk, salt, pepper and garlic. Cook just until bubbles begin to form around sides of pan. Remove from the heat; cool for 10 minutes. , Peel and thinly slice the potatoes; pat dry with paper towels. Layer half the potatoes in prepared baking dish; top with half the cream mixture and half the cheeses. Repeat layers. , Bake, covered, at 350° for 40 minutes. Uncover and continue baking until potatoes are tender, 20-25 minutes longer. Let stand for 5-10 minutes before serving.