Thinly slice 1kg (2¼lb) Dutch potatoes. Place in a basin, season with salt, pepper, and grated nutmeg and add 1beaten egg, 7½dl (1⅓pt or 3¼U.S. cups) boiled milk, and 125g4½oz) grated fresh Gruyère cheese.
Mix well together then fill into well-buttered dishes which have been rubbed with garlic. Sprinkle the surface liberally with more cheese and butter and cook in a moderate oven for 40–45 minutes.