These succulent beans were traditionally made with dark amber syrup, but lighter grades can be substituted. Adjust the sweetness to suit your taste.
Wash and pick over the beans, cover with cold water, and soak overnight. Drain and rinse beans again, place in a large pot, and cover with cold water. Bring to a boil, reduce heat, and simmer for about 45 minutes, or until the skins wrinkle. Place the whole onion in the bottom of a bean pot or deep 4-quart casserole. Combine beans, maple syrup, mustard, and salt and add to pot. Score the salt pork and place it on top of the beans. Add water to cover. Cook at 325 degrees F for about 8 hours. Check and add water as needed. Remove cover for last hour to brown salt pork.