Bain-marie (also known as a water bath or double boiler) is a cooking technique that involves using a container filled with hot water to gently heat food items. The food item is placed in a smaller container, which is then placed in a larger container filled with hot water. The hot water provides indirect heat to the food item, preventing it from coming into direct contact with the heat source and reducing the risk of overcooking or burning.
This technique is commonly used for melting chocolate or preparing delicate sauces, custards, and desserts that require gentle and even heating. The bain-marie technique can also be used to keep food items warm for extended periods of time.