These Korean-style barbecued ribs are served with pickled Taiwan bok choy; the greens are infused with the flavors of rice-wine vinegar, ginger, toasted sesame oil, garlic, chiles, and scallions
Cut each short rib crosswise into 3 pieces, cutting between the bones. Soak ribs in a large bowl of ice-water for at least 20 minutes, or up to 2 hours.
Make marinade: Stir together marinade ingredients in a medium bowl until sugar is dissolved. Drain ribs; pat dry. Put ribs and marinade in a 9-by-13-inch glass baking dish; turn each rib to coat. Cover, and refrigerate overnight.
Make pickled greens: Put greens and scallions in a medium bowl, and set aside. Cook garlic and chiles in sesame oil in a small saucepan over medium heat until garlic is pale golden, 2 to 3 minutes. Add ginger, and cook, stirring, until fragrant, about 2 minutes.
Remove from heat; stir in vinegar, mirin, and the salt. Immediately pour contents of pan over greens, and toss to coat. Let cool to room temperature. Cover with plastic wrap; refrigerate overnight.
Preheat broiler, with the rack about 6 inches from heat source. Line a rimmed baking sheet with foil, and very lightly brush with vegetable oil. Lift ribs from marinade, and arrange in a single layer on sheet (discard marinade).
Broil ribs (checking often) until well browned on top, about 5 minutes. Turn; continue to cook until well browned on other side, about 4 minutes more. Serve with chilled pickled greens.
Both the ribs and the greens need to marinate overnight, so plan accordingly.