Combine all the ingredients for the marinade in a porcelain-enameled container. Add the meat and for best results marinate for 10 days, if not more. Turn twice daily. When ready to cook, presoak a large clay pot, top and bottom, in water for 15 minutes. Remove the meat from marinade, put in a large frying pan, and sear on all sides in the hot bacon fat. Meanwhile, pour the marinade into a saucepan and reduce to 1/3 its original volume by boiling rapidly, uncovered. Place the meat in the presoaked pot, then add the marinade and all the other ingredients except the arrowroot. Cover the pot and place it in a cold oven. Set the oven temperature at 425 degrees. Cook for 2 to 2 1/2 hours, until almost done, then remove the po from the oven and pour off the sauce. Return the pot to the oven, uncovered, for a final 10 minutes of cooking. Meanwhile, put the sauce into a blender container and blend. Taste for seasoning; the sauce should be "sweet and sour." If not, add brown sugar and/or vinegar. Heat the sauce, thicken with the arrowroot, and serve over the meat and German potato pancakes.