
Roux is a mixture of wheat flour and fat, traditionally clarified butter. It is the thickening agent of three of the mother sauces of classical French cooking.
Béchamel sauce also known as white sauce, is a basic sauce that is used as the base for other sauces, such as Mornay sauce, which is Béchamel and cheese. This basic sauce, one of the mother sauces of French cuisine, is usually made today by whisking scalded milk gradually into a white flour-butter roux (equal part clarified butter and flour), though it can also be made by whisking a kneaded flour-butter beurre manié into scalded milk. The thickness of the final sauce depends on the proportions of milk and flour.
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