Slow Cooker Variation
Soak and drain beans. Layer half the salt pork in a slow cooker. Add beans, onions, and apple cider, just enough to barely cover (supplement with cold water if needed). In a separate bowl, whisk together slightly warmed molasses, mustard, and salt; pour over beans. Top with remaining salt pork. Cook on HIGH for 3-6 hours, then reduce to LOW for 1-4 more hours, until beans are tender.