Bearnaise Sauce (recipe)

In A Small Sauce Pan Combine Shallots And Vinegar And Simmer Until Reduced To 1/4 Cup. Strain And Set Aside. Place Egg Yolks In Top Of A Double Boiler Over Hot But Not Boiling Water. Beat With Wire Whisk Until Yolk Are Fluffy. (Eggs Will Curdle If Water Boils.) Add 1/4 Cup Melted Butter And Beat Constantly Until Butter Is Completely Absorbed By The Yolks, And The Sauce Thickens. Continue Adding Remaining Butter, 2 Tablespoons At A Time, Stirring Constantly. Add Lemon Juice And The Reduced Shallot-Vinegar Mixture. Sauce Will Be Thin At First But Continue To Stir With Whisk Until It Begins To Thicken. Taste And Add Salt, Pepper, And Parsely, Tarragon And Chervil. Note: If Sauce Curdles, Add 1 Tablespoon Boiling Water And Beat Continually To Rebuild Smoothness.