Preheat oven to 150°C. Season pork chunks with cumin, oregano, salt, and pepper.

Heat vegetable oil in a large Dutch oven over medium-high heat. Sear pork in batches until browned on all sides, about 3-4 minutes per batch. Remove and set aside.

Add onion and garlic to the pot and cook for 2 minutes. Return pork to the pot with orange juice, lime juice, and chicken stock.

Cover and braise in the oven for 2.5 to 3 hours until pork is fork-tender and reaches an internal temperature of at least 75°C.

While pork braises, char the poblano peppers under a broiler or over a gas flame until blistered on all sides. Place in a bowl, cover with plastic wrap, and let steam for 10 minutes. Peel off skins, cut a slit lengthwise, and carefully remove seeds, keeping peppers intact.

For the tomatillo crema, place tomatillos and jalapeño on a baking sheet and broil for 8-10 minutes until charred. Let cool slightly.

Blend charred tomatillos, jalapeño, sour cream, cilantro, and a pinch of salt until smooth. Set aside.

Once pork is cooked, shred with two forks and mix with some of the braising liquid to keep it moist. Combine shredded carnitas with cooked rice.

Increase oven temperature to 190°C. Stuff each poblano pepper generously with the carnitas and rice mixture. Place in a baking dish.

Top stuffed peppers with shredded Monterey Jack cheese. Bake for 15-18 minutes until cheese is melted and bubbly.

Drizzle generously with tomatillo crema, garnish with fresh cilantro, and serve immediately.