Peel each onion, cut about a quarter inch from root end and reserve. Scoop insides until sides are about a quarter inch thick. Put pork, smoked pork and scooped-out insides of onions through a meat grinder. Mix with eggs, bread roll crumbs, spices and parsley. Fill onions with mixture.
Fry smoked bacon and put a slice on each onion. Place the cut-off onion ends back on top of the bacon. Roast onions in a casserole with some water and without lid for about 45 minutes at 400 degrees F. When done, remove from casserole. Pour drippings into a skillet. Add brown meat stock, flour, spices and Schlenkerla Smokebeer. Heat and stir until gravy becomes thick.
Serve with mashed or boiled potatoes, ladling gravy over onions and potatoes.