This is a rich egg-based sauce flavored with a bit of lemon or vinegar, butter and a hint of cayenne pepper. It can be served over vegetables, fish, or Eggs Benedict. A successful sauce is made in a double boiler. Be sure not to allow the water in the bottom of the double boiler to boil, just to remain hot and lightly simmering. A tablespoon of cold water can be added to reduce the heat of the water if it starts to boil. The sauce should be served immediately.
½ cup (1 stick) unsalted butter
2 tablespoons white-wine or tarragon vinegar or fresh lemon juice
4 tablespoons boiling water
3 large egg yolks
¼ teaspoon cayenne pepper
½ teaspoon salt
In a small saucepan on low heat, melt the butter and keep it warm. In another small saucepan on low heat, heat the vinegar or lemon juice until just warm. Have a small saucepan with boiling water and a measuring tablespoon ready. Place the top of a double boiler over (not in) hot water. Place the egg yolks in the top of a double boiler and whisk until they begin to thicken. Now add 1 tablespoon of the boiling water. Continue to beat the sauce until it begins to thicken. Repeat with the remaining water, 1 tablespoon at a time, beating the mixture after each addition. Add the warmed vinegar or lemon juice. Remove the double boiler from the heat. Beat the sauce briskly with a wire whisk. Continue to beat the mixture as you slowly pour in the melted butter. Add the salt and cayenne and beat the sauce until it is thick. Serve immediately.
YIELD: 1 CUP