White sauce is one of the basic sauce. In general, seafood and white meat are used in white sauce and others are known as red sauce, caviar, white sauce and so on. It's done with butter, fried mushrooms and onions, and then put them into flour, butter, and so forth, with some nice, tall soup to be added to the sauce, and easily with boiled water instead of high soup. The sauce is black pepper and salt, so thick it's better to have white wine, so light milk and salt..