In a medium bowl, combine minced lemongrass, shallot, garlic, brown sugar, fish sauce, soy sauce, rice wine vinegar, black pepper, and oil. Mix until well blended into a fragrant marinade.

Rinse the pork loin chops under cold water and pat them dry with paper towels. Make 3-4 small slits in the connective tissue to help the marinade penetrate deeply.

Place the pork chops in a Ziploc bag or a large bowl, pour in the prepared marinade, and massage the mixture into the chops until thoroughly coated. Seal or cover and refrigerate for at least 12 hours.

When ready to cook, take the marinated pork chops out of the fridge and let them sit at room temperature for 15 minutes.

Preheat a grill pan over medium-high heat. Sear the chops for about 4 minutes on each side until charred and an instant-read thermometer reads between 140°F and 145°F.

Remove the pork chops from the heat and cover loosely with foil. Let them rest for 5 minutes before serving.