Preparation

In a small bowl, whisk all ingredients except butter.  Set aside.  

Cook butter on high just until melted.  If it has bubbled, cool it a bit.  

Stir egg yolks vigorously while adding butter in a thin stream.  Cook on 50% power 1 1/2 - 2 minutes, whisking well every 30 seconds, until desired thickness is reached.  If you have doubled or tripled the recipe, you will need to do this last step longer.