Heat olive oil in heavy pot or casserole. Add onions, bay leaves and a large pinch of salt, saute over medium heat until starting to soften and change colour.
Add garlic and fennel seeds, mix everything together and continue cooking for another 2 or 3 minutes before adding chorizo. Cook 10 minutes or so, letting chorizo release its oil and flavor everything.
This is a good time to peel and chop your celeriac if you haven't done so already. When you're ready, add this to pot and stir well. Add tomatoes and sugar and allow everything to fry for a few minutes before pouring in stock and chickpeas. Bring everything to boil then turn the heat down, cover and simmer about 30 minutes.
Meanwhile wash the kale well and remove and discard tough stalks. Roughly shred and add to pot. Continue cooking for another 30 minutes, removing lid for final 15. Before serving, check seasoning, adding more salt and black pepper. To serve, add a scattering of chopped parsley if you have it.