1 Season the pork: In a small bowl, combine the spice rub ingredients. Pat the pork dry with paper towels, then sprinkle with half of the spice rub. Turn and rub the spice into the pork until the pieces are evenly coated.
Leave the pork to absorb the rub and to take the chill off the meat, at least 15 minutes or up to an hour. (Room temperature pork will sear better!)
2 Sear the pork: Select the “Sauté” program on your pressure cooker and add the oil to the pot. (If you are using a stovetop pressure cooker, heat the oil over medium heat.)
Use a pair of tongs to lower the pork into the pot so the side with the most fat is facing down. Sear for 5 minutes. Flip it over and sear it for 5 more minutes. Both sides should be browned.
3 Sprinkle the remaining spice rub over the pork, then pour the pineapple juice over the top.
4 Cook the pork: Place the lid on your pressure cooker. Make sure that the pressure regulator is set to the “Sealing” position. Select the “Manual” program on the pressure cooker and set the time to 50 minutes at high pressure. (For stovetop pressure cookers, cook for 45 minutes at high pressure.)
It will take about 10 minutes for your pressure cooker to come up to pressure, and then the 50 minutes of actual cooking will begin.
5 Release the pressure: You can either perform a quick pressure release by immediately moving the vent from “Sealing” to “Venting” (be careful of the steam!), or you can let the pot depressurize naturally, which takes about 20 minutes. (For stovetop pressure cookers, perform a quick pressure release.)
6 Separate the pork and cooking liquid: Use tongs to transfer the pork to a plate or carving board. Use heat-proof mitts to lift the inner pot out of the pressure cooker, pour the cooking liquid into a fat separator, then pour the liquid back into the pot. Reserve the fat.
(Alternatively, let the cooking liquid stand for about 10 minutes until the fat floats to the top, then use a shallow spoon to skim as much fat as possible from the surface.)
7 Reduce the cooking liquid: Return the pot to the pressure cooker, select the “Sauté” program, and let the cooking liquid reduce for 10 minutes. (If you are using a stovetop pressure cooker, do the same thing over medium heat.)
8 While the liquid is reducing, use a pair of forks to shred the pork.
9 Toss the shredded pork with the reduced liquid and serve: Return the pork to the pot with the reduced cooking liquid and toss to coat the pork evenly. If the pork seems a little dry, add a tablespoon or two of the reserved fat.
Serve it in tacos with the fixings listed above, or in burritos or rice bowls, or on a tostada salad.