Mix together the red wine, finely sliced Onion, celery and peppercorns and marinate the meat for 48 hours; drain and dry.
Make a few incisions in the meat with the point of a knife and insert the prosciutto after coating it with pepper.
Heat the oil and 30 g [1 oz] butter in a large pan and brown the meat for 4 minutes.
Moisten with the white wine and allow to evaporate.
Add the bunch of mixed herbs (tie it up to prevent the herbs from dispersing into the sauce) the lemon peel (sliced), salt, freshly ground pepper and stock, then cook, covered, over a low heat for about 3 hours, adding warm water if necessary.
Transfer the cooked meat to a serving dish; stir the remaining butter together with the flour into the pan juices and cook for a few minutes before pouring over the meat.
Since boar meat is not always readily available, Pork may be used instead, in which case marinating time should be reduced by at least 12 hours.