01 - In a mixing bowl, whisk together the gochujang, soy sauce, brown sugar, sesame oil, minced garlic, grated ginger, rice vinegar, mirin if using, and black pepper until a smooth, uniform paste forms.
02 - Place the trimmed lamb ribs in a large resealable bag or shallow dish. Pour the marinade over the ribs, massaging to coat every surface thoroughly. Seal and refrigerate for at least 4 hours, preferably overnight for maximum flavor penetration.
03 - Preheat the oven to 320°F. Remove the ribs from the marinade, reserving any excess. Set the ribs on a wire rack placed over a rimmed baking sheet and cover tightly with aluminum foil.
04 - Roast the covered ribs for 1 hour. Meanwhile, pour the reserved marinade into a small saucepan, stir in the honey, and simmer over low heat for 5 minutes until reduced to a glossy glaze.
05 - Raise the oven temperature to 400°F. Uncover the ribs and brush generously on all sides with the honey-glaze mixture. Continue roasting uncovered for 10 to 15 minutes until deeply caramelized with slight charring at the edges.
06 - Remove the ribs from the oven and let rest for 5 minutes. Squeeze yuzu juice liberally over the surface of the ribs.
07 - Scatter sliced scallions, toasted sesame seeds, and sliced red chili over the ribs. Cut between the bones into individual ribs and serve immediately with steamed rice or pickled vegetables.