Wash the meat and put it in a saucepan. Peel 2 onions and carrots each, cut them into large pieces and add them to the meat. Add water until the meat is covered. Season with salt and peppercorns.
Bring to the boil, cover and allow to simmer at low heat for about 1 1/2 hours. In the meantime peel the remaining onions and cut them into rings. Peel remaining carrots and potatoes, clean and wash leek.
Cut or slice the vegetables into thin slices at an angle. Cut potatoes into 1-2 cm cubes and store in water. Remove some meat stock and cook carrots and leek for about 10 minutes.
Take the meat out and cut into slices. Melt 2 tablespoons of fat in a pan. Fry the potatoes and onions in it, take them out. Add 1 tablespoon of fat to the frying fat. Fry the slices of meat in it from each side until crispy.
Arrange meat, vegetables, potatoes and onion rings on plates. Serve with finely sliced horseradish.