Peel, wash and cut the potatoes into pieces. Clean the cabbage, quarter it, wash it and cut out the stalk. Cut cabbage into pieces. Peel and finely chop the onion. Heat oil in a pot. Braise potatoes, onion and cabbage in it. Add a good 1 litre of water, bring to the boil and stir in the stock.
Cover and simmer for about 15 minutes. Cut beetroot into small pieces. Cut the sausage into slices and add it to the cabbage with the beetroot, cook for another 3 minutes. Season borscht with salt, pepper, vinegar and possibly caraway. Wash the chives. Fill the borscht on deep plates. Put a blob of sour cream on each plate and cut the chives into small rolls