Dab the meat dry, peel 1 onion and cut in half. Roast the cut surfaces in a pan without fat for about 5 minutes until dark. Bring 3 litres of water, bay leaf, cloves, some salt, roasted onion and peppercorns to the boil in a large pot.
Add meat and simmer at medium heat for about 2 1/2 hours.
Clean or peel and wash the soup greens. Cut about half of the celeriac into 2-3 pieces. Cut the leek roughly into pieces. Add celery and leek pieces to the meat. Skim off any foam from the broth in between.
Peel and wash the carrots and potatoes and cut them into cubes of about 2 cm width. Cut the remaining celery into cubes of approx. 2 cm. Cook with carrots and potatoes in salt water for about 5 minutes. Remove meat from the stock.
Pour stock through a fine sieve, collect, measure 500 ml stock. Cut the meat into slices, keep warm in the remaining stock. Melt the fat in a saucepan. Stir in flour and sweat briefly.
Add the measured stock and milk. Add horseradish while stirring. Bring the sauce to the boil, simmer for about 3 minutes. Keep warm.
Wash and clean the beans and cook in salted water for about 12 minutes. Peel the remaining onion and dice finely. Heat the oil in a pan. Fry onions, potatoes, carrots and celery for 3-4 minutes.
Drain the beans. Arrange meat, sauce, beans and roasted vegetable cubes on plates. Garnish with parsley. Add remaining sauce.