Soak salt cod in three changes of water in the refrigerator to remove salt (48 hours), then drain.
Meanwhile, drain chickpeas and cook in a saucepan of boiling water until tender (30-40 minutes). Set aside.
Bring celery, onion, carrot, bay leaf, peppercorns and 3 litres water to the boil in a large saucepan, add salt cod and simmer over medium heat until tender (40 minutes). Drain (discard vegetables), cool, break salt cod into large chunks and set aside.
Heat olive oil in a saucepan over medium heat, add onion and stir occasionally until tender (20 minutes). Add garlic, anchovies and chilli and cook until anchovies dissolve (2 minutes). Add cavolo nero and cook until wilted (2 minutes), then add 250ml water and simmer until evaporated (10 minutes). Add tomatoes and another 250ml water, or enough to make a soupy consistency, and simmer until cavolo nero is tender (10 minutes). Add salt cod and chickpeas and serve hot.
This recipe is from the March 2013 issue of Australian Gourmet Traveller.