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.
Chocolate gravy
Milk is commonly used as the liquid in chocolate gravy, while some recipes use water. Some recipes devised in eastern Oklahoma use more sugar, and the fat comes from the use of butter after the gravy is complete, making it more like warm chocolate pudding served over biscuits. In a traditional gravy, a roux is made with fat and flour before the milk is added; in chocolate gravy all the dry ingredients are mixed first, milk slowly incorporated, then stirred continuously until cooked. When a thick and rich consistency is achieved, the butter and vanilla are added. Other ingredients, such as crumbled bacon, are usually added afterward near the end of preparation.