In a small bowl, combine the brown sugar, Hawaiian salt, paprika, cumin, coriander and black pepper.
Cut the pork into 4 equal portions, then tie each cut with some butcher's twine. Lightly sprinkle each piece with 1 1/2 teaspoons of the spice mixture.
Preheat the oven to 300 degrees F.
Heat 3 tablespoons canola oil in a large Dutch oven over medium heat. Sear each cut of pork on all sides, then transfer them to a plate. Add the remaining 1 tablespoon canola oil to the same pot along with the onions, ginger, and garlic. Saute for 2 minutes. Pour in the pineapple juice and chicken stock and return the pork to the pot. Cover put the pot into the oven to braise until the pork is fork tender, about for 2 1/2 hours.
Remove the pork from the Dutch oven and arrange the pieces on a baking sheet. Sprinkle each piece with the remaining 1/2 teaspoon of the spice mixture and put them under a low broiler until their tops are brown and crisp but not burned, about 2 minutes. Transfer the pork to a serving platter and serve with a drizzle of braising liquid.