Step 1

Heat the olive oil in a large saucepan and cook the leeks and celery over medium-low heat for 5 minutes or until soft. Add the carrots and the boiling stock or water and bring to the boil over high heat. Reduce heat to medium-low and simmer for 10 minutes.

Step 2

Add the zucchini, green beans and borlotti beans, and simmer for 5 minutes or until the beans are heated through and the vegetables are just tender.

Step 3

Slip the fish fillets into the soup and simmer for a further 5 minutes. Season with salt and pepper, then ladle the soup into bowls, placing the fish on top.

Step 4

Spoon a dollop of pesto on top of the fish, scatter with parsley and serve.