01 - In a large bowl, combine soy sauce, gochujang, sesame oil, honey, minced garlic, grated ginger, rice vinegar, brown sugar, black pepper, and chopped spring onions. Whisk until smooth and fully incorporated.
02 - Place the lamb ribs in a large resealable bag or shallow dish. Pour the marinade over the ribs, turning to coat evenly on all sides. Seal and refrigerate for at least 1 hour, preferably overnight for deeper flavor penetration.
03 - Preheat oven to 320°F. Line a baking sheet with aluminum foil and place a wire rack on top. Arrange the marinated ribs on the rack in a single layer, reserving any leftover marinade for basting.
04 - Roast the ribs for 1 hour, basting with the reserved marinade halfway through cooking to build layers of flavor and keep the meat moist.
05 - Preheat a grill or broiler to high heat. Transfer the roasted ribs to the grill and cook for 3 to 5 minutes per side until the exterior is deeply caramelized and lightly charred in spots.
06 - Remove the ribs from heat and immediately squeeze fresh yuzu juice over the top. Sprinkle generously with toasted sesame seeds, thinly sliced spring onions, and sliced red chili if desired.
07 - Serve the ribs hot with extra yuzu wedges on the side for squeezing.