You use a bain marie for melting chocolate or if you are cooking or baking something that calls for a custard-like mixture. You can also use a bain marie to heat up breast milk in a bottle for a baby.
bain- marie
Some desserts need a lower cooking heat, or the tempture of the bain-marie which a stove top doesnt have
60 degrees or above
Bain Marie is also known as a double broiler is used to cook foods such as custards, melting chocolates, some gravies, and other delicate dishes such as mousses.
You can use bain marie very easily in a buffet. There are many types of bain marie equipment that can be plugged into a wall outlet, filled with water and let to warm up. There is also a type that runs off of a burner, but those are not as efficient.
Using a wet Bain Marie
Because creme brûlée needs slow cooking, so the egg yolks on the creme brûlée dont get overcooked, bain marie guarantees that the temperature around the ramekins doesn't raise above 100C, because that's the temperature when water boils, water never gets its temperature above that level. Also, bain marie guarantees an even temperature which is desirable for such a delicate dessert.
The bain Marie method of cooking is cooking in a water bath. You can slow cook using this method. This method is used in order to slowly cook items. It is used when you do not want to raise the temperature too much or too quickly.
The cast of Bain de minuit - 2006 includes: Doriand as Doriand Dominique Hulin Veroushka Knoge Marie Ravel Christophe Salengro Peter Von Poehl
A Bain Marie is a "water bath" method of cooking. It is used to surround the actual cooking container (like a small ceramic ramekin) with an inch or so of warm water in the oven to cook items gently and thoroughly. Typically custards are cooked in this method as the eggs need this gentle heat to remain tender and not tough.
Seeing as this is in Food and Cooking, I'll assume you really mean 'bain Marie'. This is a large double cooking pot, or a pot on top of a slightly larger one, used to boil vegetables.