Al Pastor

Tear the guajillo and ancho chilies open and remove all seeds and veins. Heat a dry comal or cast-iron skillet over medium heat until very hot. Press each chili flat with a spatula and toast for 20–30 seconds per side — until fragrant and pliable, with a couple of small dark spots. Do not let them turn black, or the entire marinade will taste of ash. Transfer immediately to a bowl and cover with just-boiled water. Weight them down with a small plate and soak for 20 minutes until completely soft and yielding.

Drain the chilies, reserving 60ml of soaking water. Combine soaked chilies, achiote paste, pineapple, onion, garlic, vinegar, oregano, cumin, salt, and oil in a blender. Add the reserved soaking water. Blend on high for 2–3 minutes until completely smooth — there should be no visible chili skin or fibre. Taste and adjust: it should be deeply smoky, mildly tangy from the vinegar and pineapple, pleasantly spiced, and the salt should be at the front of your tongue. If too thick to blend, add soaking water one tablespoon at a time.

Place the thinly sliced pork shoulder in a large bowl or zip-lock bag. Pour all of the marinade over the pork and toss thoroughly until every surface is evenly coated in the deep red paste. The pineapple enzymes (bromelain) will begin tenderizing the meat almost immediately — this is why the marinating time should not exceed 8 hours or the pork surface will become mushy. Cover and refrigerate for a minimum of 4 hours, ideally overnight (but not more than 8 hours for thin-cut shoulder).

Position the oven rack at the highest position and set the broiler to its highest setting. Line a heavy baking sheet with foil. Lay the marinated pork slices in a single layer — they may overlap slightly. Broil for 4–5 minutes until the top surface is caramelised, blistered in places, and the edges are beginning to char. Flip each slice and broil for another 2–3 minutes. Remove and shave or chop into small pieces for tacos. Traditionally, the caramelised, slightly charred bits (the chicharitas off the trompo) are the best part — do not avoid the char.