Blender Hollandaise Sauce
["4 egg yolks", "1/4 tsp. dry mustard", "1 Tbsp. lemon juice", "1/2 c. butter, melted"]
["In blender or food processor, combine first 3 ingredients; mix until blended.", "Remove cap and pour melted butter in slow, steady stream until mixture is thoroughly mixed.", "Keep warm over hot, boiling water."]
["egg yolks", "dry mustard", "lemon juice", "butter"]