In a medium bowl, combine pepper, garlic and onion powder, thyme, oregano, brown sugar, chili, cayenne pepper, smoked paprika, and cumin until fully combined. Set aside.
Place your pork shoulder on a large cutting board, fat cap side up. Pork has a thick fat layer covering it, which can vary in thickness. When trimming the pork, make sure to have a thin layer of fat (⅛-¼ inch thick) on the outside to protect the pork as it cooks. Pat dry with paper towels.
Salt pork and rub it with seasonings, pressing them down until every inch is covered.
Place in an aluminum foil pan and let it rest for an hour (up to 24 hours), tightly covered in the refrigerator. Remove pork from the fridge about an hour before smoking to come to room temperature.
Preheat your pellet grill or smoker to 250℉/120℃. Place pork fat side up directly on grill grates, and insert a probe in the thickest part of the pork to monitor the temperature if desired. You can also start measuring for doneness towards the end.
Let it smoke for 5-6 hours, depending on the size of the roast. At this point, the pork should have a good bark. Spritz if desired, and smoke until it reaches an internal temperature of 165-175℉.
Place pork (fat side up) in an aluminum foil pan, then add pineapple sauce, hot sauce, and sliced onions. This method captures the meat's fat and juices and can flavor the pork without using BBQ sauce.
Tightly cover it with heavy-duty aluminum foil, and put it back in the smoker to continue smoking until the internal temperature reaches 205℉/96℃ or more. You shouldn't feel resistance when you probe with your instant-read thermometer.
Remove from the smoker and let it rest for at least an hour. If needed, place the pork shoulder in a cooler, without ice, for up to 3-4 hours to rest before shredding. Drain liquid from the pork and separate the fat from the juice with a separator. Use the juice to mix with the pork before serving.
Shred pork and season to taste.
Heat your corn tortillas on the grill or cast-iron skillet. Fill each one with a spoonful of pulled pork and fill it with your choice of toppings. Enjoy