Roux
Roux () is flour and fat cooked together and used to thicken sauces. Roux is typically made from equal parts of flour and fat by weight. The flour is added to the melted fat or oil on the stove top, blended until smooth, and cooked to the desired level of brownness. Butter, vegetable oils, bacon drippings or lard are commonly used fats. Roux is used as a thickening agent for gravy, sauces, soups and stews. It provides the base for a dish, and other ingredients are added after the roux is complete.
Roux
The fat is heated in a pot or pan, melting it if necessary. Then the flour is added. The mixture is heated and stirred until the flour is incorporated, and then cooked until at least the point where a raw flour taste is no longer apparent and the desired colour has been reached. The final colour can range from nearly white to nearly black, depending on the length of time it is heated and its intended use. The end result is a thickening and flavoring agent.