If using dried, pre-soaked beans, drain & rinse them, put them in a pan, cover with water and simmer for an hour until cooked. Drain and leave on one side until required. On top of the stove, fry the onions and garlic in the oil in a large, heavy casserole dish until lightly browned. Add the paprika and a little filtered water to make a rich sauce. Add the molasses, tomato ketchup and tomato puree and add water, little by little, to make a thickish sauce.