Follow directions on the bag of lima beans for soaking and/or pre-cooking
In a large pot, using a small amount of oil, saute onion and and celery until soft. Add chopped carrots and soaked beans. Cover with water and simmer until beans are tender. About 1 hour.
Add ham bone and continue to cook, over low heat, for at least two more hours or until ham falls off the bone.
Remove ham bone. Stir in large can of tomatoes, molasses, Worcestershire sauce, dry mustard, ketchup, and tomato paste.
Cut meat from bone into bite size pieces and return to pot for at least another hour, over low heat, until the flavors have blended.