Heat the oil in a pot over medium heat. Add the onions and cook until tender, about 5 minutes. Stir in the remaining ingredients, except the pork chops. Reduce the heat to medium-low. Gently simmer the sauce for 20 minutes, stirring occasionally. Remove the sauce from the heat. Preheat your barbecue to medium-high. Lightly oil the grill. Season the pork chops with salt and pepper. Grill the chops for 3 to 4 minutes per side, or until just cooked through. Brush the chops generously on both sides with the barbecue sauce; heat through and serve. Serve any extra sauce alongside for dipping.