1Heat oven to 400ºF. Place beef, fat side up, on rack in shallow roasting pan. (For easy cleanup, line the roasting pan with aluminum foil before placing beef on rack.) Insert meat thermometer so tip is in center of thickest part of beef.
2Roast uncovered 30 to 40 minutes or until thermometer reads 140ºF. Beef will continue to cook after being removed from oven. Cover beef loosely with tent of aluminum foil and let stand 15 to 20 minutes or until temperature rises to 145ºF.
3While beef is standing, stir together wine, tarragon and vinegar in 1-quart saucepan. Heat to boiling over medium-high heat. Boil 2 to 3 minutes or until mixture is slightly reduced. Reduce heat to very low. Stir in egg yolks one at a time with wire whisk until well blended. Cook and stir with wire whisk 2 minutes or until mixture begins to thicken. Stir in orange juice and melted butter with wire whisk until smooth. Serve warm over tenderloin.