Combine the black pepper, herbs from Provence, sweet paprika, coarse sea salt, finely chopped garlic, and chilli flakes into a rub. Vigorously rub the entire pork neck with this spice mixture.
Place the seasoned pork neck in a large freezer bag and refrigerate for 3 hours. Remove from the refrigerator 20-30 minutes before grilling.
Prepare the grill for indirect grilling.
Place the pork neck on a lightly oiled grill rack, or in an aluminum dish, or in a roasting rack. Close the grill lid. Maintain grill temperature between 140-170°C (284-338°F), checking and adjusting every 15-20 minutes.
Combine the balsamic vinegar, white wine, and brown sugar in a bowl. Brush the roast with this sauce every 20 minutes during grilling.
Insert a meat thermometer into the thickest part of the roast. When the internal temperature reaches 72°C (162°F), the roast is done.
For a crispier exterior, increase the grill temperature for the final 20 minutes of cooking.
Remove the roast from the grill and let it rest for 10 minutes before serving.