Supreme sauce

Suprême sauce is a classic and popular "daughter sauce" of French cuisine. It consists of velouté, a "mother sauce", thickened with cream and strained. According the Larousse Gastronomique, a seminal work of French haute cuisine, first published in 1938, suprême sauce is made from the mother sauce velouté , reduced with heavy cream or crème fraîche, and then strained through a fine sieve. A light squeeze of lemon juice is commonly added. In many cases, chefs also choose to add finely chopped and lightly sautéed mushrooms to the dish, although this was not specifically mentioned in Larousse Gastronomique or by Auguste Escoffier, the "Emperor of the World's Kitchens", who was an arbiter of classic French cuisine.

Source: Wikipedia