Preparation: Wash the meat, dab dry and season with salt and pepper. Heat oil in a roasting pan. Brown the meat all around. Add 1 3/4 litre of warm water and bring to the boil. Peel onions and add them to the meat together with the bay leaves and peppercorns.
Cook everything on low heat for 2 1/2 hours. In the meantime, clean and wash the Brussels sprouts. Wash carrots and parsley root and cut into thin slices. Heat 30 g fat in a pot.
Sauté the vegetables in it, steam with 1/8 litre water and bring to the boil. Season with salt and pepper and cook for about 15 minutes. Take the meat out and keep warm. Wash the apple, cut 2 slices out of the middle.
Grate the rest of the apple. Heat the remaining fat, sauté the apple slices in it and remove. Add flour to the frying fat and sweat it. Deglaze with 1/2 litre meat stock. Add grated apple, horseradish and cream.
Season to taste with salt and pepper. Arrange meat, vegetables and some sauce on a plate. Garnish with parsley and apple slices. Add remaining sauce extra.