After Julia.
Add 1 T finely minced shallots and 1/2 t dried tarragon with 1/4 t each salt and pepper to 1/4 c dry white vermouth, 1/8 c gin, 1/8 c water and 1/2 c good red wine vinegar and boil down to 2 T. Cool down in an ice bath.
Slice 4 T butter individually and make sure it stays cold. Melt 6 T butter and set aside.
Separate 3 egg yolks and whip in a flat saucepan till pale yellow, add the liquid and 2 T cold butter and turn heat on to med-low. Whip moderately till you can see the bottom of the pan between whips. At once add 1T cold butter to arrest the cooking - continued whisking - followed by another when the first has melted. Then drizzle in small amounts of the melted butte thickening as you go.
Makes 1 c. - serve over beef tenderloin. Don't reheat in the microwave or it will curdle.