01 - In a large mixing bowl, combine the soy sauce, gochujang, sesame oil, honey, minced garlic, grated ginger, rice vinegar, brown sugar, black pepper, and chopped spring onions. Whisk until fully incorporated and smooth.
02 - Place the lamb ribs in a large resealable bag or shallow dish. Pour the marinade over the ribs, turning to coat every surface evenly. Seal tightly and refrigerate for at least 1 hour, preferably overnight for deeper flavor penetration.
03 - Preheat the oven to 320°F (160°C). 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 in the oven for 1 hour, basting generously with the reserved marinade at the halfway mark to build layers of glaze.
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 the heat. Squeeze fresh yuzu juice generously over the top, then sprinkle with toasted sesame seeds, sliced spring onions, and sliced red chili if desired. Serve immediately with extra yuzu wedges on the side.