Flavignan Sauce

Pound half a pound of very fat chicken livers, two ounces of butter, one tablespoonful of chopped parsley and a pinch of finely cut tarragon; have three gills of port wine in a saucepan with one pint of espagnole (No. 414), add to it salt, pepper, coriander seeds, cinnamon and sugar, boil it for a few minutes, and then mix in the pounded livers, stirring them in well; boil again for a few minutes longer and strain through a tammy; finish with two ounces of butter before serving.