Hollandaise sauce

Method

1. Have the butter at room temperature, and cut into small pieces, each equivalent to about a teaspoonful.
2. Put a piece of butter with the lemon juice, egg yolks and water in the top half of a double-boiler, or in a bowl. Beat well for 1 minute, until combined. Place over a saucepan of barely simmering water, mix in the salt and pepper, and beat until it thickens to a smooth cream.
3. If the sauce thickens too quickly, and becomes lumpy, immediately stand the bowl or pan in cold water, then return to the heat, and beat until thick and smooth. Turn off the heat, or remove from the stove, and add the butter one piece at a time, stirring briskly until each piece is well incorporated. For perfect smoothness, it is essential to keep beating without stopping between additions of butter. Taste and correct seasoning, if necessary.
4. Serve warm, not hot, as soon as possible. If sauce is to be kept, keep it no longer than 1 hour, put over a pan of lukewarm water and, just before serving, beat in 1 teaspoon of tepid water.