Step 1 of 5
Summer Pistou
Heat the oil in a large pan and fry the leeks and zucchini for 5 minutes until softened.
Step 2
Pour in the stock, add three-quarters of the cannellini beans, the green beans and half the tomatoes. Simmer for 5–8 minutes until the vegetables are tender.
Step 3
Meanwhile, blend the remaining cannellini beans and tomatoes with the garlic and basil in a food processor (or with a stick blender) until smooth. Stir in the Parmesan to make the pistou sauce.
Step 4
Stir the pistou into the soup and cook for 1 minute.
Step 5
Ladle into bowls and serve.
