Gather the ingredients.
Season the pork neck with the salt, fish sauce, sugar, and garlic. Set aside to marinate at room temperature for at least 30 minutes.
Heat the grill to high and grill the pork on each side without moving for 5 minutes or until charred and marked by the grill. Continue to grill until the meat is cooked through to 145 F internally (this will depend on the thickness of the cut). You can check the doneness by poking a knife into the middle of the pork neck to check for tenderness. Remove the pork from the grill and let rest.
Meanwhile, make the dressing. In a bowl, stir to combine the onion, spring onion, cilantro, fish sauce, lime juice, sugar, and chili flakes.
Slice the pork against the grain and add to the bowl with the dressing.
Toss gently and serve with sticky rice or on a bed of lettuce. Enjoy!