3 egg yolks
1/2 teaspoon salt
Dash of cayenne pepper
1 tablespoon heavy cream
1 cup unsalted butter, melted
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. While blender is running begin adding hot butter in a thin, steady stream.
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.
Makes about 1 1/2 cups sauce.