Heat the oil in a large saucepan or casserole, and in it gently fry the onions, celery, carrots and garlic until soft; this will take 20 to 30 minutes and is what gives the soup its underlying depth of flavour. Stir in the chopped tomatoes, and cook until most of the liquid from them has evaporated. Add the stock, bring to the boil, and simmer while you prepare the green vegetables.
Shred the cabbage, slice or dice the courgettes, and break up the beans. Add to the simmering stock and cook until the vegetables are tender. Stir in the chopped herbs, season at this point, and ladle into hot soup bowls, with a little more olive oil floated on top. Pasta can be added to the soup when you put in the green vegetables, and canned beans added towards the end for a one-pot meal.
© 2000 Frances Bissell. All rights reserved.