Place water, celery, carrot, onion, garlic, parsley, bay leaves and salt in a large pan; bring to the boil. Reduce heat. Simmer, covered, for about 25 minutes, to make a stock. While the stock simmers, peel the beetroots and turnip, adding all the peel to the pan. Chop the beetroots and turnip into small pieces.
Heat oil in a large saucepan over medium heat. Add the chopped onion. Sauté until softened, about 5 minutes. Add the beetroot, turnip and cabbage. Strain the stock, discarding the vegetables. Add the stock to the beetroot mixture. Simmer, uncovered, until root vegetables are tender, about 20 minutes.
Remove from heat. Stir in dill and lemon juice. Cool to room temperature. Cover; refrigerate until cold. Whisk in sour cream just before serving.
on the menu
Traditionally, warm boiled potatoes are eaten as an accompaniment to the borscht. They are served on a separate plate, sprinkled with chopped chives. Instead of mixing the sour cream into the soup, it is served in a bowl so that people can add it to both the soup and the potatoes, as they like.