This pocket of Kanda has several long-running restaurants in vintage wooden buildings. Isegen, in business since the 1830s, occupies a handsome one from 1930 with a communal tatami dining room. The speciality here is ankō-nabe (monkfish hotpot; ¥3500 per person, minimum order for two). Get a side of kimo-zashi (monkfish liver; ¥1400) – a prized delicacy, served pâté-style.
Cheaper lunchtime options include yanagawa-nabe (loach in rich egg and dashi stock; ¥1800).