1Pat pork shoulder chunks dry with paper towels and season generously with salt and pepper.
2Heat a dutch oven or heavy skillet over medium-high heat. Working in batches, sear pork chunks on all sides until deeply browned, about 3–4 minutes per side. Transfer to a plate.
3Add quartered onion and garlic to the pot, scraping up browned bits. Cook 2 minutes until fragrant.
4Return pork to pot. Add oregano, cumin, bay leaves, orange juice, and chicken broth. Stir to combine.
5Cover and transfer to a 325°F oven, or use a slow cooker on low. Cook for 3–3.5 hours until pork is fall-apart tender.
6Remove from heat and discard the bay leaves. Let cool slightly, then shred meat with two forks directly in the pot, discarding any large fat chunks. Taste and adjust salt and pepper.
7Warm tortillas in a dry skillet or over a gas flame until pliable.
8Serve carnitas in tortillas topped with sliced white onion, cilantro, and a squeeze of lime.