Fry the meat in butter until slightly brown. Remove from pan. Dice bacon rashers and fry with the sliced onion and mushrooms, adding a little more butter if necessary.Add the flour and cook until brown.
Add stock or water and bring to the boil stirring constantly.Place the meat in a casserole dish and add the sauce. Put the peppercorns and Allspice into a muslin bag and place in casserole. Cook slowly in a pre-heated oven at 160C for 2 hours. Remove spice bag and serve. Optional: A glass of red wine can be added to the stock before cooking if desired.