3 egg yolks
 1/2 teaspoon salt
 Dash of cayenne pepper
 1 tablespoon cream
 1 cup (1/2 pound) melted sweet butter, heated until bubbling but not brown
 1 tablespoon lemon juice or white wine vinegar

Place egg yolks, salt, pepper and cream in blender, blend for a few seconds at high speed until you have a smooth frothy mixture. Still at high speed, start adding hot butter in a thin, steady stream, not too slowly. As you add butter, the sauce should thicken. When half the butter has been added, add lemon juice or vinegar. Continue blending until all butter is used.