Peel beets and cook in salted water with peeled potatoes, 1 teaspoon caraway seeds, a sprinkle of vinegar and 1 teaspoon sugar, 2 cloves of garlic until soft.
Mix the beets with the potatoes and garlic cloves and add enough stock to make the soup thick.
Stir the starch with the cream and add to the soup. Bring to the boil again and finally stir in freshly grated horseradish to taste.