In a large skillet, heat oil over medium-high heat. Season pork chops with salt and pepper, and then brown them in the hot skillet. Remove from heat.
Spray the inside surface of a slow cooker with cooking spray. Arrange sliced onions in the bottom, and place pork chops on top of onions. Sprinkle with chicken base, and top with apple pie filling. Cook on Low for 5 to 6 hours, adding sweet potatoes during the last 1 1/2 hours of cooking.