Oysters are most often served raw, on the half shell. For traditional service, they are presented in the bottom shell on a bed of crushed ice with a shallot vinaigrette (sauce mignonette) and garnished with thin slices of rye bread and lemon wedges. To cook, after opening, the oyster is cut out of the shell, reserving the liquid inside. If not being used in the immediate preparation, the liquor can be reserved—refrigerated for a day, or frozen for longer storage—for another use. Oysters may be cooked in several different ways. They can be just warmed in fumet, court bouillon, or seawater with the addition of a little white wine and diced shallots. Do not overcook or the oysters will toughen. The resulting liquid can be made into a sauce. Oysters can also be gratinéed or used in stews or soups.