Put the oil, onions, carrots, celery and garlic in a large saucepan. Cook gently over a low heat for 15 mins or until soft. Meanwhile, tip the sausage pieces into a non-stick frying pan, turn up the heat and sizzle for a few mins to brown. Put to one side.
Stir tomato purée through the soft vegetables and cook for 1 min more. Pour in the tomatoes, 3½ cans of water and the stock cube. Stir and simmer for 10 mins. Add the sausage pieces and beans, and bubble down for 10 mins until sausages are cooked through. Season and stir in the sugar, vinegar and parsley. Spoon into bowls, adding a Tapenade toast (see 'goes well with') to float, and a drizzle more olive oil, if you like.