Wash the pork shoulder roast under cool running water and pat dry. With a sharp paring knife, make 1-inch-deep incisions all over the roast. If the roast still has a thick layer of fat and skin on one side, use a sharp slicing knife to make long scores through the fat and into the meaty part of the roast in several places. The scores should penetrate the meat by at least 1/2 inch. This will be the top of your roast. (If your roast does not have any skin or exterior fat, scoring is not necessary.) Wash hands well before continuing.
Add all the remaining ingredients to a small mixing bowl and stir well to combine. Using clean hands, spread this mixture all over the roast, rubbing it in very well. Any mixture that is left may be spooned into the scores on the top of the roast, if applicable. Wash hands well.
Transfer the seasoned roast to a large nonreactive bowl and cover with plastic wrap. Refrigerate overnight.
Remove the roast from the refrigerator and allow it to come to room temperature, from 30 minutes to 1 hour, before proceeding.
Position rack in center of oven and preheat the oven to 350?F. Line a roasting pan with aluminum foil. Transfer the roast to the prepared pan and pour any accumulated juices over it. Cover with aluminum foil and bake, undisturbed, for 4 hours. Using oven mitts or pot holders, remove the foil from the roast and continue to bake, basting occasionally with the drippings from the bottom of the pan, for 2 more hours, until the roast is golden brown and crispy on the outside and the flesh is fork-tender.
Using oven mitts or pot holders, remove roast from the oven. Carefully transfer the roast to a platter or baking sheet and let rest for 20 minutes. Use two forks to pull the meat away from the bone into pieces. The meat should pull apart easily. Discard the bone and any excess fat.
Using a large spoon, skim the fat from the drippings in the bottom of the roasting pan and discard. Serve the meat with any remaining pan juices. If the juices have browned and caramelized on the pan bottom, try adding a bit of warm water and stirring to reconstitute the drippings.
Yield: 8 - 10 servings