1/2 c. butter, melted
3 egg yolks, room temperature
2 tbsp. lemon juice
1/4 tsp. salt
Few grains cayenne

Put egg yolks, lemon juice, salt and cayenne in an electric blender. Blend at low speed for a few seconds, just long enough to mix smoothly. Pour in the hot butter slowly. Blend a few seconds longer, until the sauce is smooth. Makes 1 cup.