Put one tablespoonful of butter in a saucepan. When it bubbles add one tablespoonful of flour, and cook, stirring constantly, for five minutes, but do not let it color; draw it to a cooler part of the range and add very slowly, stirring all the time, one cupful of cold milk, and stir until perfectly smooth and a little thickened. Season with salt and pepper. Most of the white sauces are simple variations from this sauce. Water may be used instead of milk, and it is then called drawn-butter sauce. It can be made richer by adding a little more butter, in small pieces, one at a time, after the milk is in; also by adding the beaten yolk of an egg. If the egg is added remove the pan from the fire and let it cool a little before adding the egg; then cook for a minute, but do not let it boil, or the egg will curdle.
The secret of making a good white sauce is in cooking the flour until the starch grains have burst, which removes the raw and pasty taste one finds where this care is not used. There is no difficulty in making it smooth if the milk is turned in slowly, as directed above. A common way of making this sauce is to rub the butter and flour together, and then stir them into the boiling milk, but this does not give as good a result as when a roux is made. The intense heat of frying butter cooks the flour quickly, while milk boiled long enough to cook the flour is changed in flavor. When this sauce is used as the basis of other sauces, the amount of salt and pepper must be varied to suit the requirements of the other ingredients.