Place beef brisket in a large pot with beef broth, white onion (halved), and garlic, then bring to a boil over high heat. Reduce to low and simmer for 3.5 hours until the meat is extremely tender and shreds easily.

Turn off the heat and let the brisket rest in the pot for 15 minutes, then remove the brisket and shred into bite-sized pieces. Reserve the cooking liquid for the consomé base.

Toast guajillo chiles and ancho chiles in a dry skillet for 1 minute, just until fragrant, then move off the heat. Soak the toasted chiles in hot water for 10 minutes to soften, then blend with garlic, tomato paste, apple cider vinegar, cumin, and oregano until smooth.

Strain the chile paste through a fine sieve into the reserved broth, scraping to capture the thick consomé. Add the bay leaf and cinnamon sticks, then simmer for 20 minutes until the broth tastes fully spiced and the color deepens.

Dip corn tortillas in consomé until lightly saturated, then fill with shredded brisket. Dip again if desired to intensify the crimson-red shell, then top with white onion and cilantro.

Serve immediately with small cups of consomé for dunking and lime wedges on the side, letting the steam lift from the broth as you eat.