In a bowl, combine oil, salt, pepper, cumin, garlic, lime, and orange juice.
Score pork and marinate with oil mixture. Place pork into cooker and set to "slow cook".
Cover with glass lid and set pressure cooker to "slow cook" for 6 hrs, flipping pork halfway through cooking.
Remove from cooker when time is up and let pork rest for 10 minutes. Shred the pork and place into cooking liquid. Build the sandwich, layering pork, ham, cheese, pickles, and mustard. Serve and enjoy.