For the Roast:
Place the pork in a large, shallow bowl lined with overlapping pieces of plastic wrap large enough to wrap around the pork. Mix the white sugar and 1 cup of the salt together in another bowl, then rub the mixture all over the meat. Cover it with plastic wrap and place in the refrigerator for at least 6 hours, or overnight.
When ready to cook, heat oven to 300 degrees. Remove pork from refrigerator and discard any juices. Place the pork in a roasting pan (preferable foil lined or a disposable foil pan) place in the oven and cook for approximately 6 hours, or until it collapses, yielding easily to the tines of a fork. (After the first hour, baste hourly with pan juices.) At this point, you may remove the meat from the oven and allow it to rest for up to an hour.
Meanwhile, make the ginger-scallion sauce and the Ssam sauce. Prepare Rice and any accompaniments.
When ready to serve the food, turn oven to 500 drees F. In a small bowl, stir together the remaining tablespoon of salt with the brown sugar. Rub this mixture all over the cooked pork. Place in oven for 10 to 15 minutes, or until a dark caramel crust has developed on the meat.
Once that last bit of sugar and salt is on there and the meat is back in a hot oven,” Chang says, “you want to watch it carefully. You’re not looking for a color so much as for the moment when the fat and the skin begins to fluff up a little. It’s not so much about the sugar caramelizing as it is about the fat starting to bubble.” When that happens — Chang calls it the soufflé effect — you are ready to go.
Serve hot, with the accompaniments.