Drain the beans and place into a large pan with fresh water and a pinch of salt. Bring to the boil and simmer for about an hour, or until just cooked. See here for a refresher on soaking and cooking beans!
Meanwhile make the sauce. Grate/chop/blitz the carrot, celery and two of the shallots. Finely chop the third shallot. Grate or crush the garlic and keep separate.
In a large saucepan, heat 2 tbsp of oil and add the veg. Fry for a couple of minutes, then lower the heat and sweat until soft and reduced almost to a puree - for about 10-15 minutes. If the veg starts to catch or stick to the pan don't add more oil, just add a splash of cold water instead, and stir well.
Add the garlic to the cooked vegetables, and cook for another minute or two. Add the bay leaf, vinegar, paprika and allspice, and mix well. Cook for another minute or two before adding the passata and water and mixing again. Bring to the boil, then reduce the heat so the sauce is just simmering. Let it cook for 30-40 minutes whilst the beans finish cooking.
Once just cooked, drain the beans and add to the sauce. Bring to the boil and simmer for another 20-30 minutes. Preheat the oven to 150C.
Taste and season the beans with salt and pepper. Transfer to an ovenproof dish, cover with foil and bake for 3-4 hours until really tender and delicious. Serve & Enjoy!