Prep: 25 mins plus overnight soaking. Cook: 2-3 hours.

1. Drain the beans and place them in a large pan with the bouquet garni and twice their volume of cold water. Bring to the boil, then boil hard for 10 minutes. Lower the heat, and simmer gently for 1–2 hours or until tender, adding more water if needed. Remove the pan from the heat, discard the bouquet garni, and leave the beans to cool in theircooking water.

2. Heat the oil in a large heavy pot, then add the onion, carrots, celery, leeks, garlic, and chilli. Cover with a lid and sweat over a low heat for 10 minutes, stirring once or twice. Add the tomatoes and tomato purée and cook over a moderate heat for 3–4 minutes. Add the beans, their cooking water and enough water to cover the vegetables generously. Season generously. Bring to the boil and simmer gently for 20 minutes or until the vegetables are tender. Purée half the soup in a blender, then return to the pan. Add the cavolo nero and simmer for 10 minutes or until tender. Adjust the seasonings.

3. Rub the bread with the garlic and arrange in a warm shallow dish or tureen. Spoon in the soup and serve with a bottle of best olive oil out on the table for people to help themselves.

Can be frozen before the cavolo nero is added and kept for up to 3 months.