Preheat oven to 350°F. Squeeze sauerkraut till quite dry.
Melt lard and sauté minced onions in it for 5 minutes.
Add sauerkraut to onions. Mix well and cook for 10 minutes. Sauerkraut should be golden fried but not burned. Remove from heat.
Mix crushed cherry pepper and black peppercorns into sauerkraut and stir well. Add 1cup water and stir again.
In a deep oblong ovenproof casserole place diced salt pork and sauerkraut. Put duck and fresh pork shoulder on top and cover the pan.
Cook in the preheated oven until duck is done, about 2 hours. Every 20 minutes or so stir the sauerkraut and turn the meats over. If necessary add a little water. Usually you don’t have to add salt; nevertheless, taste it in case some is needed.
For the last 10 minutes, increase oven heat to 450°F. Scrape off cabbage from top of meat so meat can brown.
Serve in the baking casserole, but cut the meat into serving pieces and arrange pieces on top of sauerkraut.