Season the pork: In a bowl, mix pork chunks with cumin, smoked paprika, oregano, chili powder, salt, and pepper until evenly coated.

Sear the pork: Heat olive oil in a large pot over medium-high heat. Add pork and sear until browned on all sides, about 5-7 minutes. Remove and set aside.

Cook aromatics: In the same pot, add diced onion and cook until translucent, about 3 minutes. Add minced garlic and cook for 1 more minute.

Braise the pork: Return pork to pot. Add orange juice, lime juice, and chicken broth. Bring to a simmer, then cover and cook on low heat for 1.5-2 hours until pork is tender and shreds easily.

Shred the pork: Remove pork from pot and shred with two forks. Return to pot and mix with cooking juices. Simmer uncovered for 10 minutes to reduce liquid.

Prepare toppings: While pork cooks, prepare diced onion, chopped cilantro, lime wedges, queso fresco, and sliced avocado.

Warm tortillas: Heat tortillas on a dry skillet for about 30 seconds per side until pliable and slightly charred. Keep warm in a towel.

Assemble tacos: Place shredded pork on warm tortillas. Top with diced onion, cilantro, queso fresco, and avocado. Serve with lime wedges.