Toast the dried ancho and guajillo chiles in a dry skillet over medium heat for 10–15 seconds per side, just until fragrant and slightly pliable. Do not let them smoke or blacken; burned dried chiles will make the pork bitter. Transfer the toasted chiles to a bowl, cover with hot water, and soak for 15 minutes until softened. Drain before blending. Blend the soaked chiles with the pineapple juice, white vinegar, achiote paste, garlic, brown sugar, cumin, Mexican oregano, cinnamon, and fine sea salt until completely smooth and thick. The marinade should be vivid brick-red, pourable, and free of visible chile skin. Strain if needed. Achiote paste is doing most of the colour work here — its earthy, slightly musky character combined with the rehydrated chiles is what produces the deep, unmistakable red-orange that distinguishes al pastor from other marinated pork preparations at a glance.

Partially freeze the pork shoulder for 30–45 minutes until firm but not solid. Slice it across the grain into thin 3–4mm slices, then cut very large slices into taco-sized pieces. Thin slicing is essential; thick chunks will not char quickly enough before becoming tough. Place the sliced pork in a large non-reactive container. Add the blended marinade, bay leaves, and very finely minced white onion. Massage thoroughly so the onion and marinade coat every piece. Cover and refrigerate for 6–24 hours. Do not use fresh raw pineapple juice in the marinade unless the marinating time is very short. Fresh pineapple contains bromelain and can make the pork mushy. Pasteurised pineapple juice is safer for a longer marinade. Partially freezing the pork before slicing is the detail that makes the thin, even cuts possible at all — fully soft, room-temperature pork shoulder is too pliable to slice consistently thin, while a firm, partially frozen block holds its shape under the knife the same way it would in a deli slicer.

Prepare the Homemade Corn Tortilla dough according to its separate recipe, but divide the rested dough into 24 equal balls of about 22g each instead of 8 large tortillas. Keep the dough balls covered at all times so the masa does not dry out. Press each tortilla to about 11.4cm / 4.5 inches diameter and cook on a dry hot skillet or griddle until lightly charred, flexible, and just cooked through. Stack immediately under a towel so the tortillas steam and stay pliable. The smaller taco-sized diameter keeps each open-faced tortilla in proportion to its toppings — a full-size tortilla would leave the pork, pineapple, and onion looking sparse and would be awkward to eat as a single open taco.

Toss the tomatillos, onion wedges, jalapeños, and garlic with the olive oil and salt. Broil or roast on a hot tray until the tomatillos soften, collapse slightly, and develop charred spots, about 8–12 minutes depending on broiler strength. Transfer everything to a blender with the cilantro, lime juice, and 3 tbsp water. Blend until spoonable but still slightly textured. Add more water only if needed. Taste and adjust with salt or extra lime juice. The salsa should be vivid green, bright, tangy, and loose enough to drizzle over each taco. Hold it at room temperature or chilled, depending on preference. For serving, spoon it into a small bowl beside the tacos rather than covering the pork, so the charred al pastor remains visible. Broiling rather than simmering the tomatillos develops a light char that adds real depth the raw-blended version wouldn't have — a meaningful difference given how much brightness this small side bowl needs to bring to the plate. Serving the salsa on the side rather than spooned over the tacos is a visual decision as much as a textural one — the vivid red-orange char of the pork is meant to be the centrepiece, and pooling a green sauce over it would both dull that colour contrast and soften the pork's charred edges on contact.

Toss the pineapple pieces with neutral oil and fine sea salt. Grill or sear over medium-high heat for 1–2 minutes per side, until lightly caramelised with visible char marks but still juicy. Set aside one pineapple piece per taco. Grilling the pineapple as its own separate step, rather than tucking raw pieces under the pork on the same pan, is what lets it develop its own light caramelisation and char marks while staying visibly distinct once plated — cooked directly beneath the marinating, dripping pork, it would steam rather than caramelise and disappear into the filling instead of standing out on top.

Remove the pork from the refrigerator 25–30 minutes before cooking. Lift the pork from the marinade, letting excess marinade drip off. Do not wipe it completely clean, but do not cook it while dripping wet; too much surface marinade will steam and burn before the pork chars. Heat a grill, cast-iron griddle, or large skillet over high heat until very hot and just beginning to smoke. Lightly grease the surface with neutral oil. Cook the pork in batches in a single layer for 2–3 minutes per side, until the edges are deeply caramelised, slightly blackened in spots, and the pork is cooked through. Do not overcrowd the pan. Crowding drops the heat and gives you wet red pork instead of charred al pastor. Transfer cooked pork to a board and let it rest for 5 minutes. Chop or slice into chunky taco-sized pieces, keeping the charred edges visible. The balance between "not wiped clean" and "not dripping wet" matters more here than it might seem — a thin coating of clinging marinade is what caramelises into the deep red-orange crust that defines al pastor, but a heavy wet coating simply steams off the pan's surface heat before any charring can happen.

Just before serving, rewarm the tortillas on a dry skillet for 15–20 seconds per side until soft and flexible. Keep covered in a towel. The tortillas should be warm and bendable, not crisp. This is a brief re-crisp-free warm rather than a second full cook — the tortillas were already cooked through when first pressed and griddled, so this step is purely about restoring pliability and warmth right before the tacos are built and eaten.

Place 3 warm corn tortillas per serving on plates or a wooden board. Pile each tortilla with al pastor pork, making sure some charred edges face upward. Add one grilled pineapple piece to each taco. Finish with finely diced white onion and chopped cilantro. Turning the charred edges upward and visible is a deliberate plating choice — it's the clearest signal of the meat's texture and the achiote's colour, and it's the detail that makes the finished taco read as genuine al pastor rather than simply grilled pork.

Serve 3 tacos per person with lime wedges scattered between the tacos and salsa verde in a small bowl beside them. Serve immediately while the pork is hot, the tortillas are soft, and the pineapple is still juicy. Serving immediately matters most for the pineapple and the tortillas — both lose their defining textures quickly, the pineapple's juiciness fading and the tortillas stiffening as they cool, while the pork itself holds up slightly longer.