In a large pot, heat the olive oil over medium-high heat. Add the beef chuck roast and short ribs, searing them on all sides until browned. Remove the meat and set aside.

In the same pot, add the chopped onion and garlic. Sauté for about 3-4 minutes until the onion is translucent.

Stir in the cumin, oregano, smoked paprika, chili powder, salt, and black pepper. Cook for another minute until fragrant.

Add the beef broth and water to the pot, scraping up any browned bits from the bottom. Return the meat to the pot.

In a separate bowl, soak the guajillo and ancho peppers in hot water for about 15 minutes until softened. Drain and blend the peppers with the apple cider vinegar until smooth.

Pour the blended pepper mixture into the pot with the meat. Bring to a boil, then reduce the heat to low, cover, and simmer for 2-3 hours until the meat is tender and easily shredded.

Once cooked, remove the meat from the pot and shred it using two forks. Return the shredded meat to the pot and stir to combine with the broth.

To serve, heat corn tortillas on a skillet, fill them with the birria meat, and top with chopped cilantro and diced onions. Serve with lime wedges on the side for squeezing over the tacos.