In a large bowl, combine the cumin, oregano, chili powder, salt, and black pepper. Rub the spice mixture all over the pork shoulder pieces.

Place the chopped onion, minced garlic, and pork in the crockpot. Pour the orange and lime juice over the top, then add the chicken broth.

Cover and cook on low for 8 hours or until the pork is tender and easily shreds with a fork.

Remove the pork from the crockpot and shred it with two forks. Return the shredded pork to the crockpot and mix it with the juices. Serve in tacos, burritos, or as desired.