Jangmat Son Kalguksu is a restaurant near the Seongdong Tax Office in Seongsu, Seoul, serving doenjang-based kalguksu and kimchi mandu. The noodles are made in-house and served in a savory doenjang broth with beef topping, alongside a kimchi geotjeori. Noodles and broth can be refilled continuously, and a bowl of rice is provided free on request. During lunch hours, menu orders and noodle refills take longer.