Wash the meat and dab dry. Halve the onion. Put meat in a pot and cover with water (2-3 litres). Bring bay leaf, juniper, clove, salt, onion and peppercorns to the boil in a large pot and simmer over medium heat for about 2 hours.
Wash, clean or peel 1 bunch of soup greens and cut them roughly into pieces. Add vegetables to the meat after about 30 minutes. In the meantime, use a skimmer to skim the resulting foam from the broth.
Wash, clean or peel the other bunch of soup greens. Peel and wash the potatoes. Cut carrots, celery and potatoes into cubes. Cut leek into rings.
Remove meat from the stock and keep warm. Pour broth through a sieve. Measure out 1 litre of stock, pour into a wide saucepan, bring to the boil and cook the potatoes for about 20 minutes. After about 10 minutes add the remaining vegetable cubes.
Meanwhile, wash the apple and grate the flesh around the core. Mix apple, horseradish and sour cream. Season to taste with lemon juice, salt and pepper. Cut the meat into slices with a sharp knife.
Arrange bouillon vegetables, meat and apple horseradish. Use the rest of the stock for other purposes.