Season chops with salt and pepper. Heat oil in skillet and cook chops until brown and cooked through, about 5 minutes per side. Transfer to platter. Cover with foil to keep warm. Drain off all but 1 tablespoon drippings from skillet. Add butter and melt over medium heat. Add onion and apple to skillet and saute until tender, about 5 minutes.
Mix in cider, vinegar and bay leaf. Cover skillet and cook 10 minutes. Discard bay leaf. Add any accumulated juices from pork chop platter to skillet. Increase heat to cook until sauce thickens slightly, about 3 minutes. Spoon sauce over chops and serve.
