1/3 c Unsalted butter, softened 1 3/4 tb Heavy cream
1 Fillet of beef, about 3-3-1/ 3/8 c Shallots, minced lb, tied, room temp 1 2/3 c Dry white wine
Directions
Step #1 Rub the fillet with the oil, Spice up this with salt & pepper and, in a large roasting pan, roast in a preheated 550f oven for 23 mins or until a meat thermometer registers 130f for medium rare.
Step #2 Transfer to a platter & let stand, loosely covered with foil, for 15 mins.
Step #3 In a bowl, cream the butter & mustard.
Step #4 In a large saucepan, wine, mix the shallot, and tarragon & cook the mixture over mod-high heat until wine is reduced to about 1 c.
Step #5 Add the cream & cornichons, a little at a time, reduce heat to low, & whisk in the mustard butter, with any meat juices that have accumulated on the platter.
Step #6 Spice up the sauce with salt & pepper & keep it warm, but do not boil.