Old-Mat Jjajang is a Chinese restaurant in Seoul that serves old-style jjajangmyeon, jjamppong, and tangsuyuk. The noodles are made with rice flour, which gives them a chewy texture, and the jjajangmyeon is not too sweet. The jjamppong broth is clean and light, and the tangsuyuk is crisp and savory. The overall flavor is on the mild side.