Cut pork into 5 to 6 large chunks. Season each piece evenly with salt, pepper, garlic powder, chili powder, and cumin.

Heat oil in a large skillet over high heat. Add pork in a single layer to the hot skillet. Cook untouched until well browned on one side, about 4 to 5 minutes. Flip and cook for another 3 to 4 minutes. Remove meat and place into the bottom of a slow cooker.

To the hot skillet, add onion and cook 1 minute. Deglaze pan with orange juice, lime juice, and 1 1/4 cups water. Scrape up any browned bits and pour the mixture over pork in the slow cooker. Add bay leaves and cover.

Cook on High for 4 to 5 hours or on Low for 6 to 7 hours, or until pork is very tender.

Preheat the oven to broil. Remove pork from the slow cooker, shred into large pieces, and place on a rimmed baking sheet. Spoon some of the juices over the pork and broil for 3 to 5 minutes until crispy, tossing halfway through.