in a small bowl, combine the cumin, oregano + salt.evenly rub the spices onto the pork shoulder.heat olive oil in a large skillet over medium-high + sear the pork until browned on all sides {about 8 minutes}transfer the pork to a slow cooker.add the smashed garlic, onion, orange juice + lime juice over the top of the pork.cook on low for 6-8 hours {3-4 hours on high}, or until the meat falls apart.remove the pork from the juices in the slow cooker and to a cutting board. you may choose to shred it or slice the pork as best as you can.heat a grill over medium heat.lightly butter the outside {top + bottom ala grilled cheese style} of the bread + build your sandwich from the bottom up: folded ham slice, roasted pork pieces, swiss cheese, dill pickles + mustard.grill the sandwich until golden, remove to a plate + enjoy!