Step 1

Place beans in a bowl. Cover with cold water. Set aside for 8 hours or overnight to soak. Drain. Place in a saucepan. Cover with cold water. Bring to the boil over mediumhigh heat. Cook for 10 minutes. Drain well.

Step 2

Heat the oil in a non-stick frying pan over medium heat. Cook the onion, celery, carrot and pancetta, stirring, for 5 minutes or until soft. Add the garlic, rosemary and chilli. Cook, stirring, for 1 minute or until aromatic.

Step 3

Place the onion mixture, beans, stock and water in a large (6L) slow cooker. Cover. Cook on low for 6-7 hours. Stir through the cavolo nero and season with black pepper.

Step 4

Spread bread with pesto. Divide soup among bowls. Top with herbs. Serve with toast.