To roast the poblano chile, turn a gas burner to high and place the chile directly over the flame. Roast, turning as needed, until the skin is blackened and blistered, about 2 minutes per side. If you don’t have a gas stove, you can roast the poblano using a broiler or a grill. Transfer to a bowl, cover with plastic wrap, and let steam for 10 minutes. Peel off and discard the charred skin, remove the seeds, and roughly chop.

To toast the chiles, heat a large Carbon Steel Frying Pan over medium. Toast the guajillo, ancho, pasilla, and árbol chiles in batches, pressing them flat with a Spatula for about 15 seconds per side, until fragrant. Transfer to a bowl and cover with 2 cups hot water to soften, about 10 minutes.

To blend the sauce, add chopped poblano, softened dried chiles (with their soaking liquid), tomatoes, vinegar, sesame seeds, smoked paprika, allspice, black pepper, cloves, and ginger to the pitcher of a blender. Blend until smooth, scraping the sides as needed.

If using the optional marrow bones, preheat the oven to 450F. Line a Sheet Pan with foil and place the bones on top, with marrow facing up. Roast until the marrow is hot and bubbly, about 15 minutes. Set aside.

Preheat oven to 300F. Season short ribs generously with kosher salt. Heat oil in a large Dutch Oven over medium-high. Sear the short ribs in batches until deeply browned on all sides, 2–3 minutes per side. Remove and set aside. In the same Dutch Oven, add sliced onions and sauté until golden brown, about 5 minutes. Add garlic and stir for 30 seconds until fragrant.

To braise the meat, return short ribs to the Dutch Oven and carefully pour the blended sauce over top. Add the cinnamon stick, bay leaf, and enough beef stock to fully submerge the meat. Cover and braise in the oven until the meat is fall-apart tender, 4–5 hours. Skim about half of the fat from the braising liquid.

To serve, remove the short ribs from the Dutch Oven, shred the meat, and return it to the consommé. Serve with warm tortillas, cilantro, onions, and lime wedges. For crispy birria tacos, dip tortillas in the consommé, crisp them on both sides on a Carbon Steel Griddle, fill with birria, and serve with the garnishes and strained consommé for dipping.