¼ cup wine vinegar      ¼ cup dry white vermouth
1 T. minced shallots      ½ tsp. tarragon
¼ tsp. salt      ¼ tsp. pepper
3 eggs 
4 T. cold, unsalted butter
1 stick unsalted butter, melted 
Directions:  Boil down vinegar, vermouth, shallots, tarragon, salt, and pepper.  When 
reduced to about 2 T., set aside.
In a sauce pan, vigorously whisk the egg yolks for a good minute or so, until they are 
thick and pale yellow.  Add vermouth mixture.  Add 2 T. cold butter, which while 
melting slowly will act as a kind of anti-curdling insurance.
Set the pan over low heat, whisking at a moderate pace and watching carefully until in a 
minute or more the egg yolks have thickened and the bottom of the pan can be seen 
between strokes.  At once remove from heat and beat in remaining butter, one 
tablespoon at a time, to stop the cooking.
By driblets, best in the warm melted butter to make a thick sauce.
Comment: