Pulled Pork Tacos

Steps

1. Mix the cumin, smoked paprika, chipotle, oregano, brown sugar, 3 teaspoons of the salt, and the pepper. Cut the pork into 4 chunks about 3 inches (8 cm) across, pat them dry with paper towels, and rub them all over with the entire spice mix. You can cook them right away or refrigerate them, wrapped, for up to one night: the meat will be even better seasoned.
2. Preheat the oven to 300°F (150°C), conventional setting. Cut the yellow onion into thick slices and smash the garlic cloves with the flat of a knife. Spread them in the bottom of a 5 to 6 quart (5 to 6 liter) cast iron Dutch oven with the bay leaves, then set the pork chunks on top.
3. Juice 2 of the limes. Pour this juice and the orange juice down the side of the pot, not over the meat, so you don't rinse off the spices: the liquid should come about a third of the way up the chunks. Cover and heat over medium until you see small bubbles around the edges.
4. Transfer to the oven for 3 hours to 3 hours 30 minutes, turning the chunks halfway through. The pork is ready when a fork stuck into the center twists with no resistance and the meat reads 195 to 203°F (90 to 95°C). At 167°F (75°C) it would be cooked but still tough: you need to take it all the way.
5. While it cooks, make the pickled onions: cut the red onion into 1/16 inch (2 mm) half-moons and put them in a jar. Heat the cider vinegar, water, sugar, and 1 teaspoon of the salt until dissolved, pour it hot over the onions, and leave for at least 30 minutes at room temperature: they turn bright pink and soften.
6. Prep the toppings: mix the crème fraîche with the zest and juice of 1 lime and a pinch of salt. Shred the cabbage as thinly as you can. Pick the cilantro leaves and roughly chop them. Cut the last 2 limes into wedges. Keep everything cold.
7. Lift the pork chunks onto a platter and discard the bay leaves. Let the liquid settle for 5 minutes, then ladle off the fat that rises, setting aside 2 tablespoons of it. Mash the soft onion and garlic into the liquid, then boil over high heat for 8 to 10 minutes, until you have about 1 cup (250 ml) of syrupy juices.
8. Shred the meat with two forks, pulling out any sinew and pieces of fat that haven't rendered. Pour half the reduced juices over it, toss, taste, and adjust the salt.
9. Turn on the broiler with the rack 4 inches (10 cm) from the element. Spread the meat in a thin layer on a sheet pan, drizzle with the 2 tablespoons of reserved fat, and broil for 4 to 6 minutes, until the tips brown and crisp. Toss and give it 2 more minutes if you want it crispier, then drizzle with the rest of the juices.
10. Warm the tortillas one at a time in a very hot dry skillet, 30 to 45 seconds per side, until pliable and freckled with small brown spots. Stack them in a clean kitchen towel to keep them warm and soft.
11. Fill each tortilla with a pinch of cabbage, a good spoonful of pork, a few drained pickled onions, and cilantro, then a drizzle of lime crema. Serve with the lime wedges to squeeze over at the last minute.