Slow-Simmered Rich Bone Marrow and Shredded Beef Birria Bowl

Place the dried ancho and guajillo chilies in a small pot with 2 cups of water and bring to a boil. Turn off the heat and let them soften for 10 minutes. Transfer the softened chilies and their soaking liquid to a blender. Add the garlic cloves, apple cider vinegar, Mexican oregano, cumin, and an additional 2 cups of water. Blend on high until completely smooth, then strain through a fine-mesh sieve to remove any residual skin.

Season the bone-in beef shanks generously with sea salt on all sides. Heat the beef tallow in a heavy-bottomed Dutch oven or deep pot over medium-high heat. Sear the shanks until a deep, dark brown crust forms, about 5 minutes per side. Pour the strained chili consome directly over the seared meat, ensuring the shanks are submerged. Bring to a boil, then reduce the heat to low, cover tightly with a lid, and simmer slowly for 3 hours until the meat is completely pull-apart tender and the bone marrow is soft and buttery.

Remove the beef shanks from the pot. Pull the meat off the bone and shred it finely, discarding any gristle. Push the rich, creamy bone marrow out of the bones and stir it directly back into the simmering red consome to emulsify. Divide the shredded beef into two deep bowls, ladle a generous amount of the rich, marrow-infused hot consome over the meat, and scatter the minced onion and fresh cilantro on top to serve.