In a small bowl, whisk together the paprika, sea salt, black pepper, and thyme.

Rub the dry rub mix evenly over the ribs until they are well coated.

Brush both sides of the ribs with the BBQ sauce. Transfer the ribs to a 4- to 6-quart slow cooker. Add the onion to the slow cooker. Cover and cook on LOW for 6 hours, or until the meat is very tender.

Transfer the pork rib juices and onion to a saucepan.

Cook the sauce over low heat for 15 minutes or until reduced by one third. Pour the reduced sauce and onion over the cooked ribs.

Garnish with additional thyme leaves. Serve with additional BBQ sauce, if desired.