First, place pork shoulder on a large plate or cutting board. Remove any string using scissors and add all spices to a small mixing bowl and mix.
Pour spices over the pork shoulder and massage spices into the meat. Set aside.
Turn Instant Pot on to the saute feature and drizzle bottom of the pot with olive oil. When olive oil is fragrant, place pork shoulder in the Instant Pot. Let sear for 2 minutes on each side.
Pour green chilis over the pork shoulder, add water, and cover Instant Pot.
Turn pressure valve to seal, set pressure to high pressure, and set the timer to 90 minutes.
When meat is done cooking, quick release pressure by turning pressure valve to vent. Remove cover and pull pork apart with two forks. It should be deliciously falling apart. Remove any large chunks of fat.*
Once shredded, squeeze on lime juice.
Serve as carnitas tacos, over nachos, or in a bowl of some sort.