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
As an alternative to roux, which is high in fat and very energy-dense, some Creole chefs have experimented with toasting flour without oil in a hot pan as an addition to gumbo. Cornstarch mixed with water (slurry), arrowroot, and other agents can be used in place of roux as well. These items do not contribute to the flavor of a dish, and are used solely for thickening liquids. More recently, many chefs have turned to a group of naturally occurring chemicals known as hydrocolloids. In addition to being flavorless and possessing the ability to act as a thickening agent, the resulting texture is thought by some to be superior, and only a small amount is required for the desired effect.