For the mojo marinade: Trim the pork shoulder, removing any excess fat, and tie. Make the mojo marinade by combining the citrus juices and zest, oregano, cilantro, 1 1/2 tablespoons of the garlic and the cumin in a large mixing bowl. Whisk in the olive oil. Place the tied roast into a resealable plastic bag and pour in the marinade. Sprinkle with salt and pepper. Allow to marinate for 30 to 40 minutes at room temperature. Once marinated, remove from the bag and wipe away any excess liquid. Reserve the marinade.
For the pork roast: Preheat a 6-quart pressure cooker over medium-high heat. Add the canola oil to the pressure cooker pot and turn to high heat. Sear the roast on all sides. Then add the chicken stock, bay leaves, onions and the reserved marinade. Replace the lid and reduce the heat to low. Cook until the roast is tender, 30 to 45 minutes.
Remove the roast, transfer to a cutting board and rest for 5 to 7 minutes. Slice thinly.
For the Cuban sandwiches: Using a serrated knife, halve the Cuban loaves. Begin building the sandwiches. First, spread a thin layer of Dijon mustard onto the bread. Add 5 pickle slices, about 3 ounces of ham and a few slices of roasted pork. Top with 2 slices of the cheese. Finish with the top half of the Cuban loaf. Repeat with the remaining sandwiches.
To serve: Heat a flat-top griddle pan to medium heat with the olive oil. Place the sandwiches on to the griddle pan and place a weighted cast-iron pan on top to press. Press the sandwiches until the bread is toasted and the cheese is melted, 2 to 3 minutes. Remove and cut in half. Secure with bamboo skewers and serve immediately.