Tourin is a type of soup that originated in Southwest France. It is made from a large amount of garlic that is fried in butter with onions and then reduced with water until it is thick. An egg is added separately, the whites first and the yolk at the end, while the soup is whisked constantly to prevent the eggs from cooking into large curds over the heat. Some variations use different types of fat instead of butter, stock instead of water, and sour cream or creme fraiche in place of the eggs. When served, tourin can be poured over a toasted piece of bread, garnished with parsley and croutons, or covered in cheese and broiled quickly for a melted topping.
Garlic is the main ingredient and the primary flavor in tourin. Depending on the recipe being followed there can be as little as a handful of garlic in the dish or as much as several dozen cloves. Finely diced onions are usually added to the soup and can be used to substitute for some of the garlic to reduce the strong flavor.
The basic recipe for tourin starts with the garlic being chopped and fried in butter. Some recipes use duck fat or bacon drippings instead of butter for a different flavor. The garlic is cooked well but not browned. The onions also are cooked at this point but are not allowed to caramelize. White wine or vinegar is occasionally added near the end of the browning to provide some depth.
The fat, garlic and onions are added to a pot of boiling water. Spices such as thyme, sage or star anise can be used, but most recipes call only for salt and pepper to be added. The water is taken to a simmer and allowed to cook until it reduces. An egg white is whipped until frothy and then slowly drizzled into the tourin while it is being constantly whisked to stop the whites from forming a large, solid mass.
Just as the dish finishes cooking and is very thick and creamy in texture, an egg yolk is mixed with a small amount of vinegar. The beaten yolk is then slowly incorporated into the hot soup in the same way that the egg white was, after which the tourin is finished. It can be served in a bowl with toasted bread in the bottom, or it can be covered with a slice of Gruyere cheese and placed under a broiler for a minute so the cheese melts. Pasta or egg noodles can be added to the tourin while it is cooking to make a strong garlic-flavored pasta dish.