2While the grill heats, melt the butter in a skillet over medium heat. Add the onion, and cook until soft. Season with red pepper flakes then add the sliced apple. Stir in the sugar and balsamic vinegar, and simmer for 5 minutes, or until apples are soft and golden.
3Season the pork chops with salt and pepper. Grill for 3 to 5 minutes per side, depending on thickness. Spoon the onions and apples on top of the chops, and top with a slice of Cheddar cheese. Cover the grill, and cook for about 3 minutes until cheese is melted and bubbling.
Aluminum foil can be used to keep food moist, cook it evenly, and make clean-up easier.