Carefully boning the back of the venison along the bones. Make a sauce jus from the bones, carrots, celery, onions, pepper, salt, juniper, allspice, bay leaves and red wine. Sauté the bones with the diced root vegetables and the onions, add the spices and red wine and simmer gently for about 4–5 hours. Pour through a sieve, knead the flour and butter and thicken the sauce with it.