Trim excess fat from the pork shoulder and cut it into large chunks.

In a skillet over medium heat, sauté chopped onions and minced garlic until fragrant (about 5 minutes).

Add cumin, orange juice, salt, and pepper; stir to combine.

Transfer the mixture to a slow cooker or Dutch oven with enough water to cover the meat halfway. Cook on low for 6-8 hours until fork-tender.

Shred the pork with two forks and spread it on a baking sheet. Broil for 5-7 minutes until crispy.

Warm tortillas in a skillet before filling them with the carnitas.