Combine cumin, salt, chili powder and oregano. Rub into pork shoulder and set aside. Set instant pot to sauté and add olive oil to the pot. Working in batches brown the pork on all sides, about 3 minutes each side. This step should take about 10-15 minutes.
When pork has been seared take out of instant pot and set aside. Add onion, garlic, juice of one of the limes, bay leaf and chicken broth to the instant pot. Place seared pork on top of the onion mixture in the pot.
Seal the instant pot lid and vent, and then set instant pot to MEAT for 35 minutes. When the instant pot is finished let it slow release for at least 30 minutes but up to an hour. This is an important part of the cooking process, so I do not recommend skipping the slow release part.
Carefully remove the lid and take pork out of juices, leaving the bones, fat and bay leaf. Place pork on a plate.
If your pork had a bone then remove the bone and shred. If no bone then just shred with two forks and place on a serving dish. As a side note I tend to pick out the few large chunks of fat as it is my preference to not chew the fat, however this is simply a preference.
Add cilantro, squeeze juice of second lime, toss and serve.
Serve with my keto tortillas, cotija or feta cheese, keto slaw, and definitely avocado.