For the root meat, first rinse the beef bones under cold running water to remove the bone chips.
In a large saucepan, add cold water, salt, pepper, marjoram, peppercorns and bay leaf and bring to a slow boil.
In the meantime, clean 1.5 carrots, 1/3 of the celery, 1.5 parsley roots and the upper third of the leek and add to the soup.
Reduce the heat so that the soup does not boil too much and skim off the rising foam. After about 1 hour, add the meat, also rinsed in cold water, and simmer for 2.5 to 3 hours.
If necessary, add hot water to keep the meat covered. In the meantime, cut the rest of the vegetables into fine julienne.
Remove meat from soup and keep warm in aluminum foil. Strain soup, add vegetable julienne to soup and continue cooking until tender.
Drain all but 10 soup spoons of soup, reserving and using more. Add wine vinegar to the rest and heat briefly with the vegetables. Cut the meat into slices.
Arrange the slices of meat on warmed plates, divide the vegetable julienne among the slices of meat and pour the broth over them. Sprinkle with finely chopped chives and fresh horseradish.