Parsley, very finely chopped, is ground with a pinch of salt in a porcelain or wooden mortar. He moved to a bigger plate and to this was added powdered egg yolks, mustard, spices and lemon juice, stirring constantly, little by little vegetable oil. The mixture is diluted to the desired density with 1-2 tbsp fat-free cold broth. Stir in the cold to give a smooth sauce. Serve to cold meats and sausages.