1. Cut the cabbage, tomato and potato into rough chunks. Brown the vegetables over a low heat in a casserole with the olive oil and bay leaves.
2. After 5 minutes, add the soffritto, cinnamon, cumin and half the coriander. Add 1.5 litres of hot water, bring to a boil, add the rock salt and cook over a low heat, covered with a lid, for 30 minutes.
3. Drain the chickpeas in a colander and add them to the soup. Sprinkle with some chilli flakes and continue cooking over a low heat uncovered for another 15 minutes.
4. Cut the bread into slices and fry in hot vegetable oil: drain on kitchen paper and salt lightly. Meanwhile, cut the guanciale into 5mm strips and fry in a nonstick frying pan for 5 minutes, or until crisp. Lightly dry each strip on some kitchen paper.
5. With a handheld blender, roughly blend half the soup before returning it to the pan. Serve warm and top it with croutons, guanciale and the remaining fresh coriander.