Blanch broad beans for 2-3 minutes in boiling salted water, drain, rinse with cold water and drain again.
Cut pancetta into cubes. Cut leek lengthwise, rinse and cut into slices. Peel onion and dice finely. Rinse celery, peel carrots and potatoes. Cut vegetables into 1/2 cm (approximately 1/5 inch) cubes or slices. Rinse and spin dry spinach. Blanch tomatoes in boiling water, rinse in cold water and peel. Halve, remove seeds and chop.
Cut zucchini into slices.
Heat butter in a saucepan and cook pancetta until crispy. Add onion and leek and saute for 5 minutes. Add celery, carrots and saute for 5 minutes. Add potatoes, beans, zucchini and tomatoes and saute everything for another 5 minutes. Add 2 liters (approximately 8 cups) of water and bring to a boil. Simmer soup, covered, on low heat for about 20 minutes.
Chop garlic. Sprinkle soup with garlic, herbs and Parmesan. Serve.