Bearnaise Sauce

Serve with steak or prime rib.

1/4 cup tarragon wine vinegar
1/4 cup dry white wine
1 tablespoon minced scallion
1 1/2 teaspoons dried tarragon
1/8 teaspoon pepper
1/8 teaspoon salt
3 egg yolks
3 tablespoons boiling water
1 cup butter, sliced into thin pieces

Boil vinegar, wine, scallion, tarragon, pepper and salt over medium heat until liquid is reduced to 2 tablespoons. Cool. Place egg yolks and water in top of double boiler. Have water in bottom of double boiler shallow enough so that it doesn't touch upper saucepan. Bring water in bottom of double boiler to barely boiling. Stir egg mixture constantly with wire whisk until it begins to thicken. Do not cook too long. Remove boiler from heat and add butter, one slice at a time, beating until dissolved. Remove top of double boiler from hot water. Blend in wine and vinegar mixture. Do not use an aluminum pan. Do not let sauce stand over heat. If prepared ahead, serve at room temperature. If sauce curdles, slowly add 1 tablespoon boiling water while beating with a mixer.

Yields 1 1/2 cups.