Roux
Roux A Roux is made up of equal measures of flour and fat (normally clarified butter) combined and cooked together and for the use of thickening sauces.
Once the fat has melted the flour is added and blended until smooth, it is then cooked out to the desired level of brownness, depending on the gravy, sauce, soup or stew it is being used to thicken.
A white or blond roux would be used for sauces such as Bechamel, and a brown roux for brown sauces, casseroles and stews. Cooking out times will vary from 5/6 minutes up to 45 minutes..