Trim any excess fat from the pork chops, and heat a few of the pieces in a heavy skillet over medium-high heat until the skillet is well greased. Discard the fat, and brown each of the pork chops lightly on both sides.
Prepare four (12-inch long) pieces of heavy-duty aluminum foil. Place a pork chop in the center of each piece of foil. Top each pork chop with an apple slice, sweet potato slice, and red onion slice. Evenly distribute the savory over the top of each stack. Do the same with the nutmeg, salt, and pepper. Add a dab of butter to the top of each pork chop stack, and securely seal the meat in the foil.
Slowly grill over moderate coals; it should take 40 minutes to 1 hour, depending on the thickness of the pork chops. Turn the packet 3 or 4 times while grilling.