Donyin Diner is a restaurant in Mong Kok, Hong Kong that serves Japanese-style rice bowls and katsudon. Its signature gukongdong comes topped with sea urchin, salmon, salmon roe, botan shrimp, crab, scallop and tuna belly. Diners choose their own hoe or grilled ingredients and select a sauce, and the caramel salmon roll is brought to the table with the staff setting it alight at the edge of the plate. Lines get long during busy hours.