Heat a dry skillet over medium heat. Toast guajillo, ancho, and pasilla chiles 15–30 seconds per side until fragrant but not burned. Remove and set aside.

Rehydrate chiles

Place toasted chiles in a bowl and cover with hot water. Let sit 15 minutes until softened. Reserve soaking liquid.

Make chile puree

In a blender add softened chiles (drained, reserving 1/2 cup soaking liquid), tomato, quartered onion, garlic, apple cider vinegar, oregano, cumin, cloves, peppercorns and 1 cup beef stock. Blend until very smooth, adding up to reserved soaking liquid to reach a smooth, thick sauce (about 1/2 cup). Strain through a fine-mesh sieve into a bowl to remove skins/seeds for a silky sauce.

Sear brisket

Pat brisket dry and season lightly with 1 tsp salt. Heat 2 tbs vegetable oil in a heavy ovenproof pot or Dutch oven over medium-high heat. Brown brisket 3–4 minutes per side until a deep crust forms. Transfer brisket to a plate.

Combine and braise

Reduce heat to medium. Add the chile puree to the pot and cook 2–3 minutes to deepen flavor. Return brisket to pot, add remaining beef stock (about 3 cups) plus bay leaves and remaining 1 tsp salt. Liquid should come about halfway up the brisket; add up to 2 cups additional water if needed. Bring to a simmer, cover, and braise in a preheated 300°F (150°C) oven for 3 to 3½ hours, or until brisket is fork-tender.

Shred brisket

Remove brisket from pot and let rest 10 minutes. Shred meat with two forks into bite-sized pieces, discarding large pieces of fat. Skim fat from the surface of the braising liquid/consommé if desired. Return shredded beef to the pot to soak up consommé.

Consommé & Finishing

Strain braising liquid through a fine sieve into a saucepan and skim excess fat. Taste and adjust seasoning with salt and optional 1 tsp soy or Worcestershire for umami. Simmer consommé 5–10 minutes to concentrate if needed. Keep warm for dipping.

If consommé is too thin, simmer uncovered to reduce to a richer consistency; if too thick, thin with up to 1–2 cups water.

Squeeze lime juice over a portion of shredded beef when plating for brightness, if desired.

Quick Pickled Red Onion

If making fresh pickled onions: Combine 1/2 cup white vinegar, 1/2 cup water, 1 tsp sugar and 1/2 tsp salt in a small saucepan and bring to a simmer to dissolve sugar and salt. Place thinly sliced red onion in a jar and pour hot brine over onions. Let cool to room temperature, then refrigerate at least 30 minutes. Use 1 cup pickled onion for serving.

Tortillas & Assembly

Warm tortillas

Heat a large skillet or comal over medium heat. Brush one side of each corn tortilla with a little butter or oil. Toast tortillas in batches, 30–45 seconds per side, until pliable and lightly charred. Keep warm wrapped in a clean towel.

Assemble birria tacos

For each taco: dip one tortilla briefly in warm consommé (optional) or spoon a little consommé onto one side, place 2–3 tbs shredded beef on the tortilla, sprinkle 1–2 tbs shredded jack cheese, fold or top with a second tortilla and press briefly in skillet until cheese melts (about 30–60 seconds). Alternatively melt cheese directly on the tortilla then add beef.

Garnish and serve

Serve tacos with a small bowl of warm consommé for dipping, topped with pickled red onion and chopped cilantro. Offer lime wedges on the side. Yield about 16 tacos (serves 6–8).