Divide butter into 3 portions. Place egg yolks with 1/3 of the butter in top of a double boiler over hot (not boiling) water. Beat constantly with a wire whisk; when butter melts add another butter portion, and, as mixture thickens, add remaining butter, beating constantly.
As soon as mixture is thickened, remove from heat and add seasonings and lemon juice. Should sauce separate, beat in two tablespoons of boiling water, drop by drop. Makes 3/4 cup.