Yongchai is a Chinese restaurant near Isu Station in Seoul that serves jjamppong and guobaorou. The gogi deumppuk yuk jjamppong comes with a large amount of meat, and the guobaorou is served crispy. You can request it mild, less spicy, spicier, or with half the noodles. On weekdays seats start filling around 11:40 a.m., and by noon there are no empty seats.