Pat the brisket dry with paper towels. Rub kosher salt and freshly ground black pepper evenly over all sides of the brisket. Let sit at room temperature for 20 minutes while you prepare other ingredients.

Sear

Preheat a heavy Dutch oven or large ovenproof pot over medium-high heat. Add 2 tablespoons vegetable oil. When shimmering, sear the brisket 4–5 minutes per side until deeply browned. Remove brisket to a plate.

Sauté aromatics

Reduce heat to medium. Add the halved, sliced yellow onion to the pot and cook, stirring occasionally, until softened and starting to brown, about 6–8 minutes. Add smashed garlic and cook 30 seconds until fragrant.

Build sauce

Stir in tomato paste and cook 1 minute. Add chopped chipotle in adobo, ground cumin, dried oregano, and brown sugar; cook 30 seconds. Pour in beef broth and apple cider vinegar, scraping up brown bits from the bottom of the pot with a wooden spoon. Add bay leaf.

Braise brisket

Return the seared brisket to the pot, nestling it into the liquid and onions (fat side up). Bring to a gentle simmer on the stovetop. Cover with a tight-fitting lid and transfer to a preheated oven at 300°F (150°C). Cook until fork-tender, about 2.5–3 hours for a 2 lb brisket. Check once after 90 minutes: if liquid is low, add up to 1/2 cup beef broth.

Rest and shred

Remove brisket from oven and let rest covered for 20 minutes. Transfer brisket to a cutting board and use two forks to shred into bite-size pieces, discarding any excessively large bits of connective tissue. Skim and reserve 1/2 cup of braising liquid; mix a few tablespoons into the shredded meat to keep it moist and saucy.

Taco Assembly & Tortillas

Warm and toast tortillas: heat a cast-iron skillet or comal over medium-high heat. Lightly brush each corn tortilla with a thin film of vegetable oil. Warm each tortilla 20–30 seconds per side until pliable with a few charred spots. Keep tortillas warm wrapped in a clean kitchen towel.

Reheat brisket (if needed): if the shredded brisket has cooled, warm it gently in a skillet over medium heat with reserved braising liquid (2–3 tablespoons) until heated through, 3–5 minutes.

Assemble tacos: place about 2–3 tablespoons of shredded brisket on each warm tortilla (adjust to appetite).

Toppings & Garnishes

Top each assembled taco with a sprinkle of finely diced white onion and chopped cilantro, a pinch of crumbled queso fresco or cotija, and a few slices of pickled jalapeño to taste.

Serve with lime wedges and salsa on the side. Squeeze fresh lime over tacos just before eating.