1. For the pulled pork: Preheat the oven to 150°C. In a large, wide, oven-safe, heavy-bottomed pot, whisk together the orange juice, soy sauce, doenjang, gochujang, gochugaru, juice of 1 of the limes, and 2 cups/480 ml water until smooth. Add the pork, onions, orange halves, garlic and ginger, and stir to combine.
2. Bring to a boil over high heat; reduce the heat and simmer for about 10 minutes. Cover the pot and transfer to the oven. Cook, stirring halfway through, until the meat is very tender and falls apart easily, 2 to 2 1/2 hours.
3. Using a slotted spoon or tongs, transfer the pork to a large shallow bowl. Pass the braising liquid through a fine-mesh strainer into another large, wide, heavy-bottomed pot (or strain into a bowl and then return to the same pot); discard the solids; and skim off the fat. Bring the liquid to a gentle boil and cook until reduced by half (about 1 1/4 cups/200 ml), 10 to 15 minutes. Set aside.
4. Preheat the grill and position a rack 4 to 5 inches from the heat source. Line a baking sheet with aluminum foil.
5. When the pork is cool enough to handle, coarsely shred the meat with your fingers or two forks, discarding any bits of fat. Transfer the pork to the prepared baking sheet. Drizzle with the reduced braising liquid, season with salt and pepper, and toss gently. Spread the pork in an even layer and broil until the meat is lightly charred and crisped in spots, about 6 minutes. (Leave the grill on for the disco fries.)
6. Squeeze the juice from the remaining 2 limes (or to taste) over the pork, and toss.
7. For the disco fries: Cook the French fries according to the package instructions.
8. Meanwhile, in a small bowl, whisk the cornstarch into the stock; set the slurry aside. In a nonstick medium skillet, heat the oil over medium-high heat. Add 1 cup/225 grams of the pulled pork and cook, stirring occasionally, until heated through, about 3 minutes. Stir the slurry into the pork; cook, stirring, until the mixture thickens, about 2 minutes. Keep warm.
9. Transfer the fries to a large shallow baking dish or broiler-safe platter and season with salt. Sprinkle the cheese on top and broil until the cheese melts, about 1 minute. Spread the pork mixture on top, followed by the kimchi. Spoon small dollops of the sour cream over all, then drizzle with the Sriracha, and top with the onions, jalapenos and chives if using.
Eat the disco fries before they get all soggy.
Notes: Disco fries -- slathered with gravy and melted cheese -- are a classic diner staple in my home state of New Jersey. Here's my Korean-American version.