1 tablespoon cold water
2 tablespoon lemon juice
6 egg yolks
salt and freshly ground pepper to taste
250 g unsalted butter, cut into pieces
Place the water, lemon juice, egg yolks, salt and pepper in the top of a double boiler and whisk over simmering water until the mixture thickens. Gradually whisk in the butter, then remove the sauce from the heat and set aside in a warm place.
Makes about 1-1/2 cups.