Beurre Roux is the French word whihc literally means "brown butter", refers to butter cooked with flour as a base for a Roux Beurre is pronounced "bu-roo" and French for "butter". A Roux is a base for sauces made by combining fat or oil and flour, gently cooked and then mixed with stock, milk or whatever is required for the sauce (fresh cream), brought to the boil and simmered.