Whisk together the brown sugar, honey, fish sauce, 3 tablespoons of vegetable oil, soy sauce, Worcestershire sauce, ginger, five-spice powder, sesame oil, shallot, garlic, onion, lemon grass, salt, and pepper in a bowl, and pour into a resealable plastic bag. Add the pork chops, coat with the marinade, squeeze out excess air, and seal the bag. Marinate in the refrigerator for 8 hours.
Heat 1/4 cup of vegetable oil in a large skillet over medium-high heat or preheat an outdoor grill for medium-high heat, and lightly oil the grate. Cook until the pork chops are no longer pink in the center, about 4 minutes on each side.