Villars Sauce

Into a pint of chicken essence (No. 387) add two tablespoonfuls of rice flour diluted in a gill of cold milk, also some salt, pepper and lemon juice, two ounces of cooked chicken cut in small squares and four chopped hard-boiled egg-yolks; work the sauce steadily, reduce properly, and add one gill of double cream, and two ounces of fresh butter.