For the Spice Mix:
1 tablespoon dried onion flakes
2½ teaspoons kosher salt
2 teaspoons dried oregano
1 teaspoon cumin seeds
1 teaspoon garlic powder
½ teaspoon chipotle powder
For the Pork Shoulder:
1 pineapple, skin on and ends trimmed
3½ pounds pork shoulder or butt, cut into 2-inch chunks
1 dried guajillo chile
1 small yellow onion, quartered
2 garlic cloves, smashed
1½ cups chicken stock
¼ cup white vinegar
Flaky sea salt, to taste
12 corn tortillas
1 cup cilantro leaves
2 limes, cut into wedges
1. In a large bowl, whisk together the spice mix ingredients.
2. Stand the pineapple up on one end and, using a large knife, slice off the skins into 2-inch-wide strips. Rinse 3 to 4 strips and set aside. Halve the pineapple widthwise. Core and dice one pineapple half into ½-inch pieces and slice the remaining pineapple half into ¼-inch rounds.
3. Add the pork shoulder to the spice mix and toss to coat evenly, then transfer to the slow cooker. Add the diced pineapple, guajillo, onion and garlic. Add the chicken stock and white vinegar, and top with the reserved pineapple peels, cut-sides down.
4. Turn the slow cooker to high and cook until the meat easily pulls apart with a fork, 5 to 5½ hours. Makes about 8 cups of al pastor.
5. To serve: Pull apart the pork with a fork and transfer to a large platter with the pineapple and onions. Season with flaky sea salt and serve with the pineapple rounds, tortillas, cilantro and lime wedges.