Seopyeongok is a restaurant in the basement of the Susong Im Building in Jongno-gu, Seoul, serving North Korean-style gomtang, tangban, and mandu. The tangban comes with a rich broth and generous ingredients, and the mandu are filled with meat. On weekdays from 11:30 a.m., a line of office workers forms, food comes out quickly, and tables turn over fast, with rice and broth available for refills on request. The broth is on the salty side, so those expecting a bland gomtang will find the seasoning strong.