Combine the salt and sugar and completely cover the pork belly with the mixture. Refrigerate for 20 to 24 hours.
Preheat the oven to 300 degrees F.
Rinse the salt and sugar off the pork and transfer to a large pan. Add the carrots, celery, onions and garlic and cover with water. Cover the pan with foil or a tight-fitting lid and transfer to the oven until the pork is very tender, 13 to 15 hours.
Gently remove the pork, place in between 2 pans and refrigerate for 12 hours.
Cut the pork into 6-ounce portions and sprinkle with salt and pepper. Heat the oil in a saute pan and saute the pork skin-side down until crisp and hot.
This recipe was provided by a chef, restaurant or culinary professional and makes a large quantity. The Food Network Kitchens chefs have not tested this recipe, in the proportions indicated, and therefore, we cannot make any representation as to the results.