Heat the olive oil in a large pot and sauté the pancetta for 4-5 minutes, until starting to crisp. Add the onion, carrot and celery and continue to cook for a further 6-8 minutes, or until the vegetables are soft. Add the garlic and continue to cook for a further two minutes, before adding the tomato purée and rosemary. Stir well. Add the beans and stock and simmer for 15-20 minutes.
Remove a ladleful of the stock and beans and put them in a mini processor. Blitz to a purée and set aside. Meanwhile, add the macaroni to the pot. Continue to simmer for a further 10 minutes, or until the pasta has cooked. Return the reserved bean purée to the pot and stir through. Season with black pepper. Leave to rest for 10-15 minutes, until it’s still warm but not piping hot.
Serve the soup garnished with a little fresh rosemary and some grated parmesan.