Stir 2 oz (50 gm) of melted butter, add the egg-yolks, stirring all the while. Bring 1 cup of vegetable liquid to a boil and have it chilled. Trickle, stirring, 1 cup of the chilled liquid shaken with 4 tea-spoons of flour into it. Bring to a boil. When the sauce has thickened, add the butter, egg-yolks, and 1 cup of cream, salt, heat well without bringing to a boil.