Peel and chop the onions. Roughly dice the beetroot. Peel, wash and chop the potatoes. Heat oil in a pot. Brown the onions for about 3 minutes. Add beetroot and potatoes and fry for about 2 minutes. Deglaze with stock, bring to the boil and simmer for 15-20 minutes at medium heat
Wash herbs, shake dry. Cut the chives into diagonal rolls. Pluck dill flags from the stalks. Wash the sprouts and let them drip off
Puree the vegetables in the broth with a hand blender and pour through a sieve. Add beetroot juice and bring to the boil again. Add horseradish and buttermilk. Season to taste with salt and pepper. Pour soup into bowls. Garnish with chives, dill and beetroot sprouts