Pre-heat the oven to 180 °C, 350F gas mark 4. Bring the beans, which have been thoroughly soaked, to a boil in their soaking water. Simmer for 10 minutes, remove from the heat, strain, discard the water. Cover again with fresh water, to about 1/2 an inch above the beans. Push the cloves into the onion, and bury it and the celery in amongst the beans. Add the tomato puree, sun-dried tomatoes and soft brown sugar. Bring to the boil, cover the pot and place in the oven for 1 1/2-2 hours until the beans are completely soft and soaked up all the liquid. Check half-way through cooking time, just to make sure that all the liquid hasn't gone and it is drying out. When all the beans are soft, stir the mixture and remove the onion. If you choose, you can pull out the cloves, chop the onion and return it to the beans. Adjust the seasoning at this point, and serve with wholemeal bread.

Adapted from Michael Barry's Radio Times Cookery Year.