Simply utter the word “taco” and most people we know will get that crazed look in their eye. A look that evokes both panic (Where? Where are they? Are there enough?) and dreamy nostalgia (Remember the taco we had in L.A.? Oh, what about the ones with the chicharrón, woah were they good). The bewitching combination of sweet, salt, fat, acid, crunch, soft — not to mention handheld convenience — has entranced people for centuries. This one, like all the notable tacos that weave their way into one’s memory, takes a little time to prepare, but the results are predictably and satisfyingly delicious. Race you to the cart.
For the marinade
Heat a 10- or 12-inch cast-iron skillet over medium heat until it is almost smoking, about 5 minutes. Lightly toast the chiles until they are pliable and brown in spots, turning several times, 1 to 2 minutes total. Do not let them burn. Set aside to cool slightly. Remove and discard the stems and seeds. Put the chiles in a medium bowl.
In the same skillet, toast the cumin and coriander seeds, stirring until aromatic, about 30 seconds. Transfer to a plate to cool slightly. Grind the spices to a fine powder in a spice grinder and add to the chiles.
Still in the same skillet, char the tomato, turning with tongs from time to time, until the skin cracks and is pulling away from the flesh, with some brown spots, about 6 minutes. Remove from the pan. Use a small, sharp knife to scrape off as much of the skin as you can and discard. Roughly chop the tomato and put it in the bowl of a food processor.
Add the achiote paste and chipotle pepper to the bowl with the chiles. Pour the boiling water over all, cover with plastic wrap, and let chiles rehydrate for at least 10 minutes.
Add the chiles and their soaking liquid, chopped chorizo, onion, pineapple, mango, cilantro, jalapeño, garlic, lime and orange juices, and salt to the food processor. Pulse into an almost-smooth puree, scraping down the bowl as needed. (Makes about 3 cups.)
For the filling
Put the diced chorizo and pork in two separate bowls. Pour half the marinade into each bowl and toss to coat. Cover and refrigerate for 1 hour.
Heat the same skillet over medium heat until smoking. Shake most of the marinade off the pork slices, reserving the marinade. Working in 2 to 3 batches, brown the meat until cooked through and edges are slightly charred, about 2 minutes per side, adding oil to the skillet between batches if necessary to prevent burning. Using a metal spatula, scrape the meat and marinade from the skillet onto a plate.
Pour the marinated Chorizo into the same skillet and cook until softened, about 3 minutes. Add the reserved pork marinade and continue to cook, stirring occasionally, until thickened. Turn the heat to low.
Meanwhile, chop the pork slices into bite-sized strips. Stir the pork into the skillet and heat through. Keep warm while you prepare the tortillas and garnishes.
To warm the tortillas, use one of three methods. You can microwave them 5 at a time, covered with a damp towel, for 30 seconds. You can wrap them in foil and warm them in a 350-degree oven for about 15 minutes. Or you can heat them one at a time in a dry skillet, then keep them covered with a clean kitchen towel. Prepare the garnishes, if using.
Grab 2 tortillas and spoon some of the chorizo-and-pork mixture in the center. Top with a few pieces of pineapple and any garnishes you like.
Immigrants from the Middle East introduced vertical spit cooking to central Mexico, where the al pastor taco hails from. Traditionally, thin slices of marinated pork shoulder are stacked on a trompo (spinning top) and the vendor shaves off crispy, juicy slices directly into corn tortillas. Pineapple, aside from giving flavor and helping to caramelize, is also a meat tenderizer. Tortillas are traditionally warmed on a comal, or a flat cast-iron pan.
For the marinade
For the filling