Cabrito al Pastor

Step 1

In a small bowl, stir the achiote paste, lime juice, white vinegar, minced garlic, cumin, oregano, and salt together until smooth and well combined, about 1 minute.

Step 2

Pat the lamb shoulder dry with paper towels by pressing gently all over the surface, removing any surface moisture.

Step 3

Cut the lamb into 3-inch chunks, slicing through the grain in multiple directions to break up the muscle fibers.

Step 4

Place the lamb chunks in a large zip-top bag or bowl, pour the marinade over the meat, and turn to coat all pieces evenly.

Step 5

Seal the bag or cover the bowl, then refrigerate for 30 minutes, or while you preheat the oven.

Step 6

Set the oven to 400°F and wait until the indicator light or beep tells you it has finished heating, about 10 minutes.

Step 7

Heat 2 tablespoons of olive oil in a 12-inch cast iron skillet over medium-high heat until it shimmers and slides quickly when you tilt the pan, about 90 seconds.

Step 8

Remove the lamb from the marinade, letting excess drip back into the bag, then add the chunks to the hot skillet in a single layer, working in batches if needed.

Step 9

Sear without stirring for 3 minutes until the underside turns deep brown, the color of dark caramel, with caramelized edges visible.

Step 10

Flip each piece with tongs and sear the other side for 2 minutes until browned and caramelized like the first side.

Step 11

Transfer the entire skillet to the oven and roast uncovered for 12 minutes until the lamb is fork-tender and the internal temperature reaches 160°F on a meat thermometer.

Step 12

Remove the skillet from the oven using an oven mitt and let the meat rest in the pan for 5 minutes so the juices distribute throughout.

Step 13

Slice the white onion crosswise into thin rings about 1/8-inch thick, keeping the layers separated.

Step 14

Chop the fresh cilantro by stacking leaves, rolling them tightly, and slicing crosswise into thin ribbons about 1/4-inch wide.

Step 15

Transfer the lamb to a warm serving platter, drizzle with any pan juices, then scatter the sliced onion and cilantro on top.

Step 16

Serve with warm flour or corn tortillas and lime wedges on the side, allowing diners to build their own tacos.