Potatoes au Gratin

Peel and wash the potatoes and slice them into rounds ⅛-inch thick, using a mandoline, the slicing disk of a food processor, or a sharp knife.

Generously butter a 9-by-12-inch heavy shallow baking dish, preferably earthenware or cast-enamel, or an oval gratin dish of comparable size. (You can also use a 12-inch cast-iron skillet.) Rub the dish with half of the crushed garlic.

In a small saucepan, bring the half-and-half to a simmer with the remaining garlic and season generously with salt and pepper. Set aside.