• Combine all of the spices in a small bowl. Set aside.

Instructions for pressure cooker

• Cut the pork shoulder into 2- to 3-inch chunks.
• Add the garlic cloves, quartered onions, and cubed pork to the electric pressure cooker insert. Sprinkle the spice mixture over everything. Using your hands, toss the garlic, onions, and pork around in the spices, rubbing the spices into the meat. Add the orange and lime juice to the pressure cooker.
• Place the lid on and lock it. Cook for 25 minutes on high pressure. Depending on your preference, you can allow the pressure to release naturally or do a quick release.

Instructions for the slow cooker

• Add the garlic cloves, quartered onions, and pork to the slow cooker. Sprinkle the spice mixture over everything. Using your hands, toss the garlic, onions, and pork around in the spices, rubbing the spices into the meat. Add the orange and lime juice to the slow cooker.
• Put the lid on and cook on low for 8 hours or on high for 4-5 hours.

Instructions for both preparations after meat is finished cooking

• Now that the pork shoulder is cooked through, you'll want to crisp things up a bit. Preheat the broiler to high. Remove the pork from to a baking sheet lined with foil, and shred the meat. Spoon some of the juices and onions that are left over onto the shredded meat. Broil for 2-3 minutes.
• Remove the sheet pan from the oven and toss the meat around a bit with tongs. Pour some more of the juices over the meat and broil for 2-3 additional minutes. 
• Remove from the oven, top with chopped cilantro, and serve immediately.