Heat oil and butter in a large skillet over medium high heat. Season pork chops with salt and pepper and dredge in flour. Fry pork chops in oil until browned. While chops are browning, add the potatoes and onions to the slow cooker. Place browned pork chops over potatoes and onions and top with remaining ingredients. Cook on the low setting of your slow cooker for 3-4 hours. Garnish with chopped parsley and serve.