Instructions

1. Cut the courgettes into 2cm cubes and thickly slice the leeks.
2. Heat the oil in a large saucepan, then gently sauté the chopped vegetables for about 5 minutes, until tender.
3. Pour in the stock and bring to a simmer.
4. Meanwhile, shred the cabbage into thin strips and drain the beans.
5. When the soup is simmering, add them to it and gently cook at low temperature for 15 minutes (under cover).
6. Just before serving, stir in the lemon zest and parsley.