Make the achiote marinade: warm a little water and whisk in the Achiote Paste until smooth, then stir in Bitter Orange Juice, minced Garlic, crumbled Mexican Oregano, Ground Allspice, Ground Cumin, freshly ground Black Pepper and Kosher Salt. Add a few tablespoons of melted Pork Lard to give the marinade body and a silky texture.
Prepare the pork: trim excess fat if desired and cut the Pork Shoulder and Pork Belly into large chunks that will fit in your baking dish or slow cooker. Rub the marinade all over the meat, massaging it into crevices. Cover and refrigerate for at least 4 hours, preferably overnight, to let the flavors penetrate.
Preheat your oven to 300°F (150°C). While it heats, soften the Banana Leaf by passing it briefly over a gas flame or dipping in hot water so it becomes pliable and less likely to tear.
Assemble for roasting: lay one or two softened banana leaves in a deep baking dish, place the marinated meat on top, spoon any leftover marinade over it, then wrap the banana leaf around the pork and seal tightly with foil or kitchen twine to lock in steam.
Braise slowly: roast the wrapped pork in the oven for 3 to 4 hours, or until the meat is fork-tender and easily shredded. (Alternatively, cook on low in a slow cooker for 6–8 hours.)
While the pork cooks, make quick pickled onions: thinly slice the Red Onion and a small Habanero Chile (seeded if you prefer less heat), then toss with additional Bitter Orange Juice and a pinch of Kosher Salt. Let the mixture sit at room temperature for at least 20–30 minutes so the onions soften and turn bright pink.
Finish the pork: remove the pork from the banana leaf, reserve any pan juices, and shred the meat with two forks. Mix the shredded pork with a little of the reserved juices (and a spoonful of extra rendered Pork Lard if you like a richer texture). For a slightly crispy finish, spread the shredded pork in a hot skillet and sear briefly to caramelize edges.
Warm the Corn Tortilla on a dry skillet or comal until pliable. Assemble tacos by piling shredded cochinita onto tortillas, topping with the pickled red onions and a squeeze of Lime. Serve immediately and enjoy.
