Peel and quarter the onion. Peel and wash 1 carrot, cut into pieces. Put the meat in a large pot, add just enough cold water to cover the meat. Bring everything to the boil briefly until foam is formed. Pour away the water and remove any foam from the pot. Add 2 1/2 litres of hot water, vegetables, bay leaf, peppercorns and 1 heaped teaspoon of salt, bring to the boil. Simmer at low heat for about 2 1/2 hours. Remove meat from the stock, put aside. Pour meat stock through a sieve
Peel beetroot and 150 g carrots. Cut carrots into sticks, beetroot into cubes. Cut bacon into small cubes and let it crisp in a hot pan. Add beetroot and steam at low heat for about 10 minutes. Add tomato paste, sugar and vinegar and continue to steam briefly. Add approx. 100 ml meat stock. Add carrots, cover and cook for another 15 minutes.
Drain the sauerkraut. Peel and wash the potatoes and cut them into thicker sticks. Bring the remaining meat stock to the boil and cook the potatoes for about 15 minutes. Dice meat finely. Add beetroot mixture, sauerkraut and meat to the stock and cook for another 5 minutes. Season to taste with salt, pepper and vinegar. Wash chives, dab dry and cut into small rolls. Arrange borscht with sour cream, sprinkle with chives