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.
Tourin
Tourin () is a type of French garlic soup, also known as "le tourin d'ail doux", or "smooth garlic soup". Many regions have their own variations on the recipe. Typically, many recipes include as many as 20 cloves of garlic for a much stronger flavor. However other recipes include an equal measure of both onions and garlic to even out the taste. To prepare, the minced garlic (and sliced onions if included) are sauteed until soft and a simple roux is made by adding flour. Chicken stock or water is added to the mixture and is simmered over low heat to reduce. Egg whites are slowly drizzled in, not unlike egg drop soup, but whisked very rapidly to prevent large curds from forming. It is further thickened by tempering an egg yolk mixed with vinegar, which is then added to the soup.