This recipe is just about full-proof and delicious. It's a good way to make use out of Holiday left-overs. Also, it freezes well so you can cook it ahead of time, put it in individual containers, and have it when you want it.
Boil the ham bone and onion in a large pot of water for several hours. You may need to keep adding water as it evaporates it boils. Remove the bone when the onions have cooked down and the water has formed a broth. Rinse, the split peas in a colander and remove any discolored or defective peas. Add peas and seasonings to taste to the soup. At this point you may add, if you choose, additional ham to make a heartier soup. cook until the peas have cooked down completely and become part of the broth. You do not want chunks of peas. Add the potatos and cook until they are tender. Serve hot.