1 leek, topped and tailed
325g (12oz) carrots, peeled or scrapped
30ml (2 tbsp) sunflower oil
1 small clove garlic, crushed
grated rind and juice 1 lemon
700ml (1¼ pints) vegetable or chicken stock
30ml (2 tbsp) freshly chopped parsley
salt and freshly ground black pepper