Huntress Sauce

Put into a saucepan on the fire, two ounces of butter with two spoonfuls of chopped onions; fry these for a few minutes, then add two ounces of chopped fresh mushrooms and two ounces of unsmoked, salted beef tongue cut into dice pieces three-sixteenths of an inch. After the humidity from the mushrooms has evaporated, let them fry together without coloring. Moisten with a quart of game stock (No. 195), and half a bottle of champagne, add a bunch of parsley garnished with a bay leaf and as much thyme, and then continue to boil slowly for half an hour; strain the sauce through a fine sieve, and thicken it with four tablespoonfuls of bread-erumbs, adding one ounce of butter, a teaspoonful of chopped parsley and the juice of a lemon.