Zaru soba is Japan's answer to a hot summer's day - bundles of nutty buckwheat noodles, boiled and then plunged into icy water until perfectly firm, piled onto a bamboo tray (the 'zaru') and eaten by dipping into a small cup of savoury-sweet tsuyu sauce. It's clean, light and endlessly refreshing, the sort of lunch you'll see salarymen slurping down all over Tokyo in summer.
Don't be put off by the Japanese name for the dipping sauce - mentsuyu is really just soy sauce, mirin and dashi simmered together, and it keeps happily in the fridge for whenever the craving strikes. A fine julienne of nori seaweed scattered over the noodles and a smear of wasabi on the side are the only real garnishes needed.
This is about as low-effort as home Japanese cooking gets, but the small technique of rinsing the noodles under cold running water until the starch washes away is what separates good zaru soba from gluggy, average zaru soba. Get that right and you've got yourself a proper noodle bar lunch in about fifteen minutes.
