Pastrami Tacos with Mustard Seed Salsa

If Mexican colonists laid down roots among the Old World delicatessens of New York City, I like to imagine that this is the bastard taco they’d cook. A multi-day brine plus a 6-hour low-and-slow roast means this dish takes advance planning. But the longer you let the pastrami cure—three days is the minimum, but a week is ideal—the better chance you have at yielding insanely tender, well-seasoned meat permeated with the flavors of brown sugar and honey. The extra time pays off in shreds of coriander-scented pastrami, cut with tart pickled cabbage and mustard seeds.

For the Pastrami Brine

• 2/3 cup kosher salt

• 2/3 cup packed dark brown sugar

• 3 teaspoons pink curing salt #1

• 1 tablespoon honey

For the Filling

• 2 pounds boneless short ribs

• 1/4 cup black peppercorns

• 1/4 cup coriander seeds

For the Pickled Cabbage and Mustard Seeds

• 1 teaspoon cumin seeds

• 1 dried bay leaf

• 1 tablespoon black peppercorns

• 1 tablespoon coriander seeds

• 4 cups cider vinegar

• 1/2 medium white onion, thinly sliced

• 10 garlic cloves, peeled

• 2 tablespoons sugar

• 2 tablespoons kosher salt

• 1/2 cup mustard seeds

• 1/4 large head of green cabbage, shredded

To Assemble the Tacos

• 1/2 medium white onion, minced

• 2 limes, each cut into 6 wedges

• 1 recipe Corn or Flour Tortillas

Brine the Pastrami: In a 2-quart saucepan, combine 6 cups water with the 2/3 cup salt, brown sugar, curing salt, and honey. Bring to a simmer, then immediately remove from the heat, transfer to a bowl, and set into an ice bath to chill.

Place the short ribs in a 4-quart container with a lid. Pour the chilled brine over the meat and transfer to the refrigerator. Brine for at least 3 days and up to 1 week.

Make the Filling: Set a 12-inch cast-iron skillet over medium heat for 5 minutes. Add the peppercorns and coriander seeds and toast, shaking the pan, until fragrant, about 3 minutes. Remove from the heat, transfer to a spice grinder, and grind to a fine powder, working in batches if necessary. Set aside on a plate.

Preheat the oven to 300°F. Remove the short ribs from the brine and rinse under cold running water. Pat the meat dry with paper towels and transfer to the plate with the ground spices. Coat the meat completely with the spice rub. Nestle the short ribs in a 5 1/2-quart Dutch oven. Pour in enough water so that the short ribs are half-submerged (about 2 cups) and cover tightly with a lid. Place in the oven and cook for 6 hours, or until fork-tender. Check the short ribs periodically; you may have to continue to add water to keep the level halfway up the meat.

Make the Pickled Cabbage and Mustard Seeds: Reheat the skillet over medium heat. Add the cumin seeds and bay leaf, along with the 1 tablespoon black peppercorns and 1 tablespoon coriander seeds. Toast, shaking the pan, until fragrant, about 30 seconds. Remove from the heat and transfer to a 4-quart saucepan.

Add the cider vinegar, onion slices, garlic, sugar, and 2 tablespoons salt to the saucepan and bring to a simmer. Remove from the heat and infuse for 5 minutes. Set up a fine-mesh sieve over a bowl and pass the liquid through the strainer.

Place the mustard seeds and shredded cabbage in two separate nonreactive bowls. Pour enough pickling liquid to cover the mustard seeds, then use the remaining liquid to cover the cabbage. Place a heavy plate over the cabbage to keep it submerged. Set both aside for at least 1 hour, or until ready to use.

Remove the meat from the oven and let rest undisturbed for 1 hour at room temperature. Transfer the pastrami to a cutting board to rest. Use two forks to shred the meat and set it aside in a warm place. Make one batch of tortillas and hold them warm.

Assemble the Tacos: Lay out the warm tortillas on serving plates. Place some pickled cabbage on each tortilla and divide the pastrami evenly among the tacos. Top with the mustard seeds and minced onion. Squeeze a couple of the lime wedges over the tacos and serve the rest on the side.