One-third cup of butter, two level tablespoonfuls of flour, one-half pint of milk, three eggs, one level tablespoonful of salt, two level tablespoonfuls of sugar, two level teaspoonfuls of mustard, a speck of cayenne, one-half cup of vinegar. Put the milk into a double boiler, rub the butter and flour together, and stir them into the milk when it has reached boiling point, stir until it thickens, let it stand a moment while you mix the other ingredients. Beat the eggs until frothy, add to them the sugar, salt, mustard and cayenne, stir well until mixed, then stir in the vinegar, mix well and stir this mixture into the cream sauce in the double boiler. Continue stir ring until smooth and thick (about two minutes), and take at once from the fire. When cold this may be placed in a tightly corked bottle and kept in a cold place two weeks.