Slice the green onion into thin pieces.
In a bowl, mix together soy sauce, water, sugar, plum extract, sesame oil, ground pepper, and sliced green onion to create a flavorful marinade.
Place the pork shoulder in a large bowl or a ziplock bag. Pour the marinade over the pork, ensuring it’s fully coated.
Cover and let it marinate for at least 3 hours (overnight is best for deeper flavor).
Lightly grease the air fryer grill or tray with oil to prevent sticking.
Preheat the air fryer to 190°C (375°F) for 3-5 minutes. This helps seal in the juices when cooking.
Place the marinated pork shoulder in the air fryer basket, avoiding overlap. Cook at 190°C (375°F) for 20 minutes, flipping halfway at the 10-minute mark for even cooking. If you want a more crispy, charred surface, increase the temperature to 200°C (400°F) for the last 3 minutes.
Slice the air-fried pork into bite-sized pieces If it was not precut. Serve with lettuce, perilla leaves, and ssamjang for a delicious Korean-style ssam.