Roux 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. The fat is most often butter in
Butter into the butter. The tiny bubbles locked within the butter expand in the heat of baking and aerate the cookie or cake. Some cookies like shortbread may have no other source of moisture but the water in the butter. Pastries like pie dough incorporate pieces of solid fat into the dough, which become flat layers of fat when the dough is rolled out. During baking, the fat melts away, leaving a flaky texture. Butter, because of its flavor, is a common choice for the fat in such a dough, but it can be more difficult to work with than shortening