Pound out the pork chops to half an inch thick. If you can, control the shape to be more of a rectangle than a square, so it fits better to the shape of the bread. In a frying pan, melt the oil and 1/2 tbsp butter on medium high heat and add the onions. Saute for approx 5 minutes or until lightly golden. Add the apples and cook for approx 3 minutes or until soft and caramelized. Pour onion and apple mixture into a bowl and set aside. Season the pork chops with salt, pepper and garlic powder. Add 1/2 tbsp butter to pan and when melted add the pork chops. Cook for 5 minutes each side or until done. Add the wine (or water) to deglaze pan and cook for another 3 minutes to reduce. Cut french bread into 6 - 7 inch long portions, cut in half and spread mayonnaise and grainy mustard. Place the chops and onion/apple mixture, topped with cheddar cheese.