Genroku Udon in Seoul serves jidori, niku, and kizune udon, and has single-person tables for solo diners. Charcoal-grilled leek, a rich broth, and chewy noodles define the signature dishes. Noodle portions come in regular, double, and triple sizes, and extra noodles are free. The broth is salty, so you have to ask for the seasoning to be adjusted.