Method:

1. Place the beans in a large pot and cover with about 4lt of cold water
2. Put the whole tomato, bay leaf and olive oil into the pot and cover with a lid. Bring to the boil and simmer until the beans are plump and soft. If the water level gets low so the beans are uncovered add more boiling water so they are well covered
3. While the beans cook preheat your oven 160 degrees
4. In a separate pot or bowl combine the diced onion, pancetta, Mustard, pepper, ketchup, molasses, Worcestershire sauce and sugar
5. Once the beans are soft and fully cooked, drain off any excess liquid. (Keep the excess liquid) so that the beans are only just covered. Stir in the sauce, onion and pancetta mixture and combine well.
6. Transfer to an ovenproof dish or leave in the pot and cover with a tight lid or foil
7. Place in the preheated oven and cook for two hours. Remove from the oven and if needed add a little of the reserved water bake into the beans if they are to dry
8. Season to taste.