Fry the onion, garlic and chilli in a little water or olive oil. Add the base and stalks of the broccoli (i.e. everything except the flowerets), and the courgettes. When all this has softened sufficiently add the tomatoes and the herbs. Leave to simmer (covered) for fifteen minutes. While that is underway combine the beans, stock, soya milk, yoghurt, lemon juice, salt and pepper in a liquidiser until a smooth mixture is obtained. After the fifteen minutes are up add the bean mixture and simmer uncovered for a further five minutes. Add the corn and then enough tomato puree to take away the anaemic look. Serve on its own or with a macaroni style pasta.