Preheat your slow cooker to the low setting.

Place the bone-in ribeye roast into the slow cooker.

Season the roast evenly with sea salt and, if desired, black pepper.

Cover the slow cooker with the lid and let it cook on low for 6-8 hours or until the roast reaches your preferred level of doneness. You can use a meat thermometer to check the internal temperature; 135°F (57°C) for medium rare, 145°F (63°C) for medium, and 160°F (71°C) for medium-well.

Once the roast is done, remove it from the slow cooker and let it rest for about 10-15 minutes before carving.