Finely chop the onion, celery and garlic.
Peel the squash, then cut them into bite-sized chunks.
Roughly chop the carrot.
In a large, heavy-based pot, heat the oil, then gently sauté the onion, carrot and celery for 5 minutes until soft.
Add the garlic, squash pieces and oregano, then gently sauté the vegetables over low heat for about 5 minutes.
Stir in the tomato purée.
After a minute, add the passata and vegetable stock, then bring to the boil.
Add the pasta and chickpeas.
Simmer, uncovered, for 10 minutes. (Stir it for a couple of minutes - the pasta pieces tend to stick to the base otherwise).
When the veggies & pasta are tender, add the chopped cavolo nero and cook for another 3-5 minutes.
Stir in the parsley.
Taste the soup and season to your liking.
Serve warm.