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

Place the sliced onion and minced garlic at the bottom of the crockpot. Add the seasoned pork on top.

Pour the orange juice, lime juice, and chicken broth over the pork.

Cover and cook on low for 8 hours or on high for 4 hours, until the pork is tender and easily shredded.

Remove the pork from the crockpot and shred it using two forks. Return the shredded pork to the crockpot and mix it with the juices.

Serve in tacos, burritos, or as desired.