In a skillet over medium heat, add olive oil. Once hot, add the chopped onion and sauté until translucent, about 5 minutes. Add minced garlic and cook for another minute until fragrant.

In a blender, combine the sautéed onion and garlic, guajillo peppers, ancho peppers, cumin, oregano, smoked paprika, salt, black pepper, beef broth, and apple cider vinegar. Blend until smooth.

Place the beef chunks in the slow cooker and pour the blended sauce over the meat. Add bay leaves on top.

Cover and cook on low for 8 hours or high for 4 hours, until the beef is tender and easily shredded.

Once cooked, remove the beef from the slow cooker and shred it with two forks. Strain the broth to separate the solids and reserve the liquid as consommé.

To assemble the tacos, heat corn tortillas on a skillet until warm. Fill each tortilla with shredded beef and garnish with chopped cilantro. Serve with a small bowl of the reserved consommé for dipping.