A bain marie is simply a hot water bath and is ideal to keep foods such as sauces hot without being on a direct heat and the fear of burning the bottom of the saucepan.  This can be used in many different recipes and is simple to set up.

A step by step guide

1. A bain marie is very easy to make.  You will need a good solid metal tray that will not buckle on the heat and a metal mat of some sort to place in the bottom to stand the pans on in the tray.
2. Half fill the tray with hot water and place on top of a low heat on the hob (just enough to keep the water ticking over).
3. When required, place the saucepan onto the metal mat and cover with a lid.
4. Stir from time to time.

The bain marie should keep sauces etc. hot until required.