Take a saddle of lamb, lard it, and marinate it for twenty-four hours in a well-spiced marinade (white wine, bouquet, onions, carrots, peppercorns). Then drain it well and roast it in the ordinary way.
Put the marinade in a small saucepan, let it reduce well, squeeze through a muslin or pass through a fine strainer, add a few pieces of butter, a little stock, a small piece of butter in which flour has been worked, and a tablespoonful of red currant jelly and French mustard in equal parts. Cook slowly a few minutes, and pour this sauce, which should be very smooth and well seasoned, over the saddle carved in slin slices and remodelled.