Friends wanted to try the highly-rated Jeju Osung Traditional Restaurant (제주오성), which is reputed for serving cutlassfish / largehead hairtail fish and mackerel fish, in a couple of traditional styles. . Ambience at Jeju Osung Traditional Restaurant is modern and spacious. The brightly lit place has floor to ceiling glass panels, offering a view of the surroundings. Wide sturdy wooden tables with cushioned booth seats are neatly spread across the spacious restaurant, with green boxes separating the space. During peak periods, chatter fills the air. . Service at Jeju Osung Traditional Restaurant is attentive and efficient. Staff communicate in halting English and Mandarin, fluent Korean. The menu helpfully offers good translation with pictures, so self-service ordering is a breeze. Staff help fillet the grilled fishes tableside, a treat to watch them expertly de-bone the fish. I note they clean up quickly when diners leave. . Food at Jeju Osung Traditional Restaurant is traditional Korean cuisine, focused on grilled and braised fish dishes. Ingredients are fresh, and their popularity means good turnover throughout the day. Meals are hearty with a good range of accompaniments. Portions are large, designed for communal sharing. Prices are relatively higher than elsewhere, budget about KRW ₩33,000 / SGD $33 per person.