Seolleongtang is the ultimate Korean comfort food. In the old days, this humble beef soup was made by boiling ox bones and offal in large vats of water for hours until all that remained was a rich milky-white liquid packed with flavor. Mapo Yangji Seolleongtang has been serving seolleongtang and other variations since 1977. The addition of brisket is the secret to the extra layer of the sweet beefy flavor of the broth. An order of seolleongtang comes with rice already submerged in the hot soup.