Grilled Pork and Spring Roll Vermicelli Salad (Bún Chả Giò Nướng)

In a bowl, combine pork, fish sauce, sugar, dark soy sauce, vegetable oil, minced garlic, minced shallot, minced lemongrass, and black pepper. Mix well and marinate for at least 30 minutes, or preferably 2-4 hours in the refrigerator.