- Put the drained beans and hock in a very large pan, cover with the cold water and bring gradually to a boil.
- Leave to simmer while you prepare the other ingredients.
- In a frying pan heat the olive oil, then gently fry the onion, garlic and chile with the allspice and lemon rind, stirring occasionally, until the onions are translucent.
- Add this mixture to the beans and go on simmering for 2 hours, by which time the beans should be tender.
- At this point add the sugar, lemon juice, and tomato puree.
- Cook for another 30 minutes.
- Add salt if necessary.
- Remove the hock, and pick off any meat.
- If you would like a smooth soup, as mine (the author) was, process the mixture in batches and return with the meat to the pan.
- Otherwise, for a rougher texture crush with a potato masher.
- If the mixture seems too thick at this stage, add more water and bring back to the boil for a minute or two.