Step 1

Preheat the oven to 350 degrees F.

Step 2

Put the dried chiles on a baking sheet. Bake until slightly puffed, about 5 minutes. Meanwhile, cut the pineapple lengthwise into four pieces, then remove the core from each piece. Cut one quarter into chunks and set the rest aside.

Step 3

Heat the oil in a medium saucepan over medium heat until shimmering. Add the garlic and half the onion and cook, stirring often, until the onion is soft and translucent, about 10 minutes. Stir in the dried chiles, pineapple chunks, vinegar, salt, brown sugar, achiote paste and 1 cup water and bring to a boil. Reduce the heat and let simmer until the chiles have softened, about 10 minutes. Let cool for 10 minutes before transferring to a blender, filling only halfway. Put the lid on, leaving one corner open. Cover the lid with a kitchen towel to catch splatters, and pulse until smooth. Reserve 1 cup for later and let the rest cool completely.

Step 4

Put the pork in a large enough container to hold it comfortably and coat completely with the chile-pineapple marinade. Cover with plastic wrap and refrigerate at least 24 hours and up to 48 hours. Remove from the refrigerator 1 hour before you are ready to cook it.

Step 5

Light a pellet grill according to manufacturer's directions and set to 250 degrees F. Once lit, cover and let preheat for 15 minutes.

Step 6

Put the pork directly on the grill grate and cook until the internal temperature reaches 160 degrees F on an instant-read thermometer, about 5 hours. Remove the pork from the grill and wrap it tightly in several sheets of aluminum foil so that it is completely sealed. Increase the temperature of the grill to 275 degrees F and return the pork to the grill, putting it on a rimmed baking sheet to catch any juices that escape. Put the reserved pineapple directly on the grill grates and cook until pineapple is golden and caramelized, about 1 hour 30 minutes; remove from grill. Continue to cook the pork until the internal temperature reaches 195 degrees F on an instant-read thermometer, about 3 hours more. Remove from the grill and allow to rest 20 to 30 minutes.

Step 7

Meanwhile, once the pineapple has cooled, dice it and add it along with any juices to a medium bowl. Stir in the remaining onion along with the cilantro, lime juice and habanero chile. Season to taste with salt. Slice the pork 1/2 inch thick and cut each slice into 1/2-inch-thick strips. Serve with the salsa, reserved marinade and warm tortillas.