What is a Gratin?

A gratin is a casserole that is baked or broiled in a shallow dish, usually under a topping of grated cheese or breadcrumbs that become browned and crisp. The word gratin is derived from the French verb gratiner, which means "to brown" or "to broil." While potatoes are one of the classic vegetables used in gratins, the method can be used with all sorts of layered vegetables (and even fruits), from asparagus and fennel to tomatoes and berries.

Some gratins use creamy flour-bound sauces like bechamel and mornay to enrich and bind them, and others simply rely on heavy cream and the starch of the vegetables to act as a sauce. A cream base, however, is not a prerequisite for a gratin and can sometimes cloak the flavor of the vegetables. Broth, wine, and even the vegetables' juices (as in the Potato-Tomato Gratin in this class) can aid in cooking the vegetables and building flavor as the gratin bakes.