For gentle heat on the stove, use a slightly different kind of bain-marie, heated by steam rather than hot water. You don’t need the whole setup known as a double boiler; you can simply place a large bowl over a pot of barely simmering water, in order to gently heat eggs and dairy to room temperature for use in baking, to melt chocolate, to make certain sauces that contain egg, such as béarnaise and hollandaise, or sabayon, a classic stovetop custard. Just as the heat of a bain-marie protects custards from overcooking in the oven, it also protects them on the stove.