Brown the bones in a roasting tin in the oven; cook the onions in the butter until light brown. Put the bones, onions, beef, giblets, celery, leek, carrots, bay leaf, parsley stalks, salt and peppercorns in a large pan; pour over enough water just to cover. Bring to the boil and leave to simmer for 4 to 5 hours without stirring.
Strain the soup through a double layer of dampened muslin, and skim carefully to remove all traces of fat. If necessary, clarify the soup by pouring in 4 beaten egg whites on a very, very low heat. This collects any little particles left in the soup which can then be skimmed off.
Re-heat the soup, add the port and correct the seasoning. Serve the soup garnished with the diced cooked game meat.
© 1988 Keith Floyd estate. All rights reserved.