Remove the bones and fat from the saddle, rub the meat all over with onion, salt and pepper, and keep in a cool place for 12 hours. Chop the shallots, ham, parsley and marrow very finely, cook till slightly brown in alittle butter, season with salt and pepper, bind with the 2 eggs and, when done, stuff the saddle of mutton. Tie with string and roast, basting frequently. The gravy is strained over it when done.