Trim, wash and dry all the vegetables. Peel the beetroot, reserving 4 oz (100 g) in weight and cut all the rest, and the cabbage, carrot, leek and celery into strips. Dice the peeled potatoes.

Heat the butter in a stockpot or a very large, deep, enamelled cast iron casserole dish and fry the vegetables in it gently for about 15 minutes, stirring frequently. Add 2 pints (1.2 litres) water, the chopped, seeded tomatoes and the beef.

Add the bay leaf, bacon, a few black peppercorns and 3/4 tsp coarse sea salt. Bring to the boil, skimming off any scum that rises to the surface, then turn down the heat to very low and simmer very gently for 3 hours, or until the beef is extremely tender.

Cut the reserved raw beetroot into small pieces and grate finely, place in a piece of muslin and twist tightly to force out all the juice, collecting this in a small bowl.

Stir in a pinch of salt and the vinegar. Take the beef and bacon out of the soup, spearing them with a carving fork and cut into strips.

Return these to the soup. Add a little salt if necessary and freshly ground black pepper to taste. Draw aside from the heat, stir in the raw beetroot juice and vinegar mixture and immediately ladle into individual soup bowls.

Place 1 - 1 1/2 tbsp chilled soured cream in the centre of each serving and sprinkle with the chopped dill.