In a pot, boil the guajillo and ancho chiles in water for about 10 minutes until softened. Drain and transfer to a blender.

Add the onion, garlic, cumin, oregano, black pepper, apple cider vinegar, and 1 cup of beef broth to the blender. Blend until smooth.

In a Dutch oven, heat vegetable oil over medium-high heat. Brown the beef chunks on all sides, then remove from the pot.

Pour the blended sauce into the pot, add the beef back in, and pour in the remaining beef broth. Bring to a simmer.

Cover and cook on low heat for about 3-4 hours until the beef is tender and shreds easily.

Once the beef is cooked, shred it using two forks and mix it with the broth.

In a skillet, heat the corn tortillas one at a time until warm and pliable.

Fill each tortilla with shredded beef and a bit of broth, then fold in half.

Serve the tacos with chopped cilantro, diced onion, and lime wedges on the side.