In a medium container, mix onion, Sauterne wine, soy sauce, vegetable oil, and dry mustard. Place pork chops in the mixture. Cover, and marinate in the refrigerator 8 hours, or overnight. Turn pork chops once while marinating.
Prepare an outdoor grill for high heat, and lightly oil grate.
Arrange pork chops on the grill, and cook 5 to 7 minutes on each side, to an internal temperature of 145 degrees F (63 degrees C). Top with crushed pineapple and brown sugar before removing from heat. Discard remaining marinade.