Preheat oven to 180°C. Rub the marinade into the pork belly. Rub half the sea salt into the pork skin, drizzle with oil and rub into the skin.
Place the pork, skin-side down, on a large oven tray and cook for 1 hour.
Increase the temperature to 200°C (400°F), turn the pork, sprinkle the skin with the remaining sea salt and cook for a further 1 hour or until the skin is golden and crunchy.
Julienne carrot and cucumber, squeeze with fresh lime to dress and set aside.
Slice pork and spread mayonnaise onto halved rolls.
Fill rolls with pork, salad and garnish with fresh herbs.