Place egg yolks and 1/3 of the butter in top of double boiler. Cook over hot, not boiling, water till butter melts, stirring rapidly. Add 1/3 more of the butter and continue stirring. As mixture thickens and butter melts, add remaining butter, stirring constantly. (Water in bottom of double boiler should not touch top pan.) When butter is melted, remove pan from hot water, cook two minutes longer. Stir in vinegar 1 teaspoon at a time; season with salt and dash white pepper. Heat over hot water, stirring constantly till thickened, 2 to 3 minutes. Remove from heat at once. If sauce curdles, immediately beat in 1 or 2 tablespoons boiling water. Makes 1 cup. |