Mix the dry rub and season the pork shoulder generously. This can be done the day before - store the meat covered and refrigerated and bring it to room temperature before you roast it.  

Preheat the oven to 400 F.

Peel the pineapple and carve out 3 thickish rounds to place the pork shoulder on. Cut the rest into bite-sized pieces, cover with plastic and set aside.

Place the pineapple rounds in a roasting pan and lay the seasoned pork shoulder on top. Roast for 20 minutes and take it out. Add the pineapple juice.

Lower the oven temperature to 275-300 F depending on how strong your oven is. Continue to slow roast the pork. After one hour begin checking on the pork periodically – baste or brush it with the pan juices and turn it over as needed so that more of its surface is exposed to the dry heat of the oven. Once it begins to get tender but it is not quite fork tender add the pineapple chunks all around the meat and continue roasting. If needed add a bit of water to the pan.

Once the pork is very tender when pierced with a fork place it on a cutting board to rest for 5-10 minutes before you slice it. (Depending on the exact weight of the pork and your oven's calibration total roasting time will vary - from 2 ½ to 4 hours).

Make the glaze just before you take out the pork from the oven or while it is resting. Combine pineapple juice, hoisin sauce and brown sugar in a small sauce pan, stir to dissolve the sugar and bring to simmer over medium heat. When the mixture thickens enough to coat the back of a spoon remove it from the heat. Apply the glaze after you slice the pork roast. ****