Soak the dried chilies in hot water for about 15 minutes until they soften. Drain and blend with onion, garlic, and tomatoes until smooth.

Place beef chuck in the crock pot in a single layer, then pour the chili mixture over it.

Add beef broth, apple cider vinegar, oregano, cumin, bay leaves, salt, and pepper. Stir gently to ensure beef is submerged.

Cover and slow cook on low for 8-10 hours until beef is tender and flavorful.

Shred the beef in the crock pot using two forks and mix back into the sauce.

Heat oil in a skillet. Dip corn tortillas in broth fat, then fry for 1-2 minutes on each side until crispy.

Fill each crispy tortilla with shredded beef, fold, and return to skillet, frying until golden and crispy.

Serve hot with dipping broth, garnished with cilantro and onions.