Melt the butter over very low heat without stirring and skim off the solids floating on top.
Fill a pan about half way with water and bring it to just below boiling. Place the egg yolks in a Pyrex bowl that fits just inside the pan. Whisk in the three tablespoons of water and place bowl in the pan of simmering water. Continually whisk until egg yolks thicken and lighten (about 5 minutes).
Remove from heat and very gradually pour in the clarified butter continually whisking. Whisk in lemon juice and salt and pepper to taste. Best served immediately or warm a few seconds in the microwave. If the sauce is too thick you can whisk in a little hot water.
Makes 6 servings