Score the skin of the pork belly with a sharp knife. Make shallow cuts in a crisscross pattern to help the skin crisp up.
Season both sides of the pork belly with sea salt.
Place the pork belly in the slow cooker with the skin side up.
Cover the slow cooker with the lid.
Cook on low heat for 6-8 hours, allowing the pork belly to become tender and flavorful.
If desired, you can broil the pork belly for a few minutes to further crisp up the skin before serving.
Once cooked to your liking, slice the pork belly and serve.