Trim any excess fat, silver skin, or similar from the pork shoulder roast ready to cook.
Preheat the smoker to 250 degrees F (120 degrees C).
Rub the pork with the rub, chili powder, cumin, and pepper.
Place in the smoker and cook until it has an internal temperature of 170 degrees F (76 degrees C), about 3 hours.
In a disposable half-pan or baking tray lay out the garlic, onion, lime slices, orange juice, and oregano. Place the partly cooked pork on top then wrap tightly with foil and return to the smoker. Cook until it has an internal temperature of 205 degrees F (96 degrees C), about 3 hours.
When the pork has rested for about 30 minutes and cooled slightly pull the pork ready for the sandwich.
Sandwich
Build the sandwich on the halved Cuban rolls in the following order: mustard sauce, sliced ham, Havarti cheese, dill pickle, then finally the pulled pork.
When the sandwich is assembled, toast it in a sandwich press thus flattening a little and browning the outside while warming throughout. Serve hot.Tip: While camping this can be done on a flat top grill or in a skillet with a burger press or similar heavy object on top.