Slice off the bottom of the pineapple and stand it upright. Remove the rind in large pieces, cutting deep enough to remove all the prickles; reserve the rind. Quarter the pineapple and remove the core. Roughly chop half of the pineapple; reserve the other half for the Pineapple-Jalapeno Salsa.
To a blender, add the orange juice, vinegar, cumin, salt, oregano, smoked paprika, garlic, chipotles and adobo sauce, the roughly chopped sweet onion and the chopped pineapple. Blend until smooth. Place the pork butt in a large resealable plastic bag and add the marinade. Seal and refrigerate for 3 to 4 hours.
Preheat the oven to 350 degrees F. Set a large Dutch oven over high heat and add enough canola oil to cover the bottom. Remove the meat from the marinade and wipe off the excess. Add to the pot and sear on all sides, 4 to 5 minutes per side. Pour in the chicken stock and the marinade from the bag (the liquid should come halfway up the meat; add a little water if required). Bring to a simmer, then place the reserved pineapple rinds, skin-side up, over the top to cover. Place, uncovered, in the oven and cook until the rinds are deep brown and the pork is fork-tender, 2 1/2 to 3 hours (tent with foil if necessary).
Discard the rinds and roughly chop the meat into 1/4- to 1/2-inch pieces. Toss with a little braising liquid and keep warm.
Serve the pork in warm corn tortillas. Garnish with finely diced onion, cilantro, Pineapple-Jalapeno Salsa and cotija. Serve with a squeeze of lime.
Yield:6 to 8 servings
In a medium mixing bowl, combine the pineapple, onion, cilantro, jalapeno, lime juice, salt and chile and mix well. Allow to sit for 10 to 20 minutes before serving so that all the flavors meld together.