3 ounces dried ancho chiles – stems and seeds removed
2 ounces dried guajillo chiles – stems and seeds removed
0.25 ounces dried chiles de árbol – stems and seeds removed
3 pounds beef chuck roast – cut into 1-inch cubes
2 tablespoons beef tallow
10 ounces yellow onion – finely chopped
4 cloves garlic – minced
2 teaspoons ground cumin
1.5 teaspoons dried Mexican oregano – crumbled
2 teaspoons kosher salt
1 teaspoons black pepper – freshly ground
4 cups beef stock
2 tablespoons masa harina
1 tablespoons apple cider vinegar
Instructions
Remove stems and seeds from the dried ancho chiles, dried guajillo chiles, and dried chiles de árbol. Toast them in a dry skillet over medium heat until fragrant, 1–2 minutes, shaking often so they don’t scorch.
Bring the beef stock to a bare simmer. Transfer the toasted chiles to a heatproof bowl and pour the hot stock over them. Soak until pliable and fully softened, about 20 minutes, then blend the chiles with their soaking stock until very smooth (strain for a silkier puree if desired).
Pat the beef chuck roast dry, then season evenly with the kosher salt and black pepper.
Heat the beef tallow in a heavy pot (Dutch oven) over medium-high heat until shimmering. Brown the beef in batches without crowding, 6–8 minutes per batch, turning for deep color. Transfer browned beef to a bowl; leave the rendered fat in the pot.
Reduce heat to medium. Add the yellow onion and cook, stirring, until translucent and lightly golden at the edges, 6–8 minutes. Stir in the garlic and cook until fragrant, about 1 minute.
Pour in the chile puree and bring to a gentle simmer, scraping up any browned bits. Return the beef and any accumulated juices to the pot, stirring to coat.
Stir in the ground cumin and dried Mexican oregano. Reduce heat to low, cover partially, and simmer gently until the beef is very tender, 2–2.5 hours, stirring occasionally and maintaining a gentle bubble.
Whisk the masa harina with a ladle of hot cooking liquid to make a smooth slurry, then stir it into the pot. Simmer, uncovered, until the chili thickens and the flavors meld, 10–15 minutes.
Stir in the apple cider vinegar, turn off the heat, and let the chili rest 10 minutes before serving.