Prepare the Barbacoa: Season the Beef chuck roast generously with salt and pepper. Sear on all sides in a Dutch oven. Add the Onion, Garlic, Beef broth, Orange juice, Apple cider vinegar, Chipotle peppers, and Mexican oregano. Bring to a boil, then reduce heat and simmer, covered, for 3-4 hours, or until the beef is fork-tender. Shred the beef with two forks.