Fry flour in the butter to svetlozlatisto coloring and diluted with boiled milk. Boil the sauce, stirring, and boil for a few minutes on low heat. Season to taste with salt, sugar, white pepper, lemon juice and a pinch of lemon zest. For different cases need Bechamel sauce with a different density. With increasing liquid (broth or milk) gives a rare sauce, and an increase in the butter and flour - a thick sauce. Aromatic spices are a matter of taste.