Fresh Tomato Soup

350 g/12 oz dark mushrooms, trimmed and
finely chopped
1 onion, peeled and sliced
300 ml/1/2 pint vegetable stock
25 g/1 oz polyunsaturated margarine
25 g/1 oz plain wholemeal flour
600 ml/1 pint skimmed milk
6 tablespoons medium sherry
salt
freshly ground black pepper
6 tablespoons plain low-fat yogurt

Heat the oil in a large saucepan and fry the onion and garlic gently. Add the tomatoes to the onion with the vegetable stock, basil, salt and pepper to taste. Simmer for 10 minutes and, if wished, serve sprinkled with chopped parsley.

SERVES 4