In a small bowl, stir together oil, pepper, salt, paprika, onion powder, and garlic powder; rub mixture over chickens. In the bottom of a 6-quart slow cooker, place onions. Place chickens on onions.
Cover and cook on high 4 hours, or until a meat thermometer inserted in thickest portion registers 165°.
Recipe by Taste of the South at https://tasteofthesouthmagazine.com/easy-chicken-and-dumplings/