Combine red wine, freshly ground peppercorns, Worcestershire sauce, and mix thoroughly. Marinate lamb shank for minimum of 3 hours, but preferably overnight.
Separate lamb from marinade and set aside. In a semi-deep, coverable pan, sauté onion and garlic in enough olive oil to coat for one minute. Gently brown the lamb on all sides for about a minute or so, enough to simply sear the meat. Pour beef broth in the pan. Pour marinade into pan until it is half way to three quarters of the way up the meat and bring to a boil for 30 seconds to one minute then lower heat to simmer. Put in a bay leaves, tsp of salt, cover and cook for 3-4 hours.
After 3-4 hours take Lamb out carefully as it will most likely fall off the bone. Cover it to keep warm. Add butter, cream and 2 tbsp of flour to remaining broth and continuously stir to thicken sauce. Let simmer for about 10-15 minutes. Once thickened to a sauce-like consistency (soupy is too little, and gravy is to thick), salt to taste.