Heat olive oil in a large pot over medium heat for a minute, then add onion, carrot, celery and leek.
Cook about 10 minutes to soften vegetables, but do not let them colour.
Add water and beans; bring to a simmer.
Add shredded greens and stir until wilted. Add Parmesan rinds and simmer slowly for 1 hour.
Meanwhile, make pesto: Preferably in a mortar and pestle, otherwise a food processor,
make a puree by pounding together the garlic, pine nuts and a pinch of sea salt.
Add basil to form a paste, then fold in olive oil and parmesan. Season to taste.
After soup has cooked for 1 hour, add pasta and cook a further 15 minutes.
Season well with salt and pepper. If soup is very thick, add a glass of hot water.
Divide among 4 bowls and stir a tablespoon of pesto through each.