Peel six medium-sized, sound, cooked potatoes; cut them in halves; lay them on a dish, and season them with a pinch of salt. Pour two tablespoonfuls of melted butter over them, and roll them well in it. Arrange them on a double broiler, and broil them on a moderate fire for three minutes on each side. Place them in a hot dish, with a folded napkin, and serve.