Season the pork shoulder with salt, pepper, ground cumin, and paprika.
Heat the vegetable oil in a large skillet over medium-high heat. Add the seasoned pork shoulder and sear it on all sides until it's browned.
Remove the pork from the skillet and set it aside.
In the same skillet, add the chopped onion and garlic. Sauté until the onion is translucent.
Return the seared pork to the skillet, and pour in the barbecue sauce and chicken or vegetable broth.
Cover the skillet and let the pork simmer on low heat for about 3 hours, or until it's tender and easy to shred with a fork.
Once the pork is cooked, shred it using two forks, mixing it with the sauce in the skillet. Let it simmer for an additional 10-15 minutes to absorb the flavors.