I had to do a double take when I arrived for my lesson with Tokyo Cook, a company offering Japanese cooking classes in English that launched in March. Although the website mentions that the kitchen studio is "hidden inside the newly opened restaurant Sougo" — the less-formal sibling of Daigo, Daisuke Nomura's Michelin-starred shōjin ryōri (Buddhist vegetarian cuisine) restaurant — I hadn't expected it to be so well concealed. Finding no sign, I inquired at the bar and was led wordlessly through the dining area to a private room. Behind the sliding wooden door, a table had been set for three, and chef Shinichi Yoshida was already busy at the stove. The experience was oddly akin to walking into a speakeasy — albeit one serving healthy Japanese food instead of moonshine.

When the other guests came in, Yoshida greeted us warmly and described the menu he would be demonstrating: nasu dengaku (fried eggplant with sweet miso), shirotama zunda ae (rice dumplings with soybean paste) and homemade tofu. The lesson began with an introduction to dashi, the broth made from kelp and bonito flakes, which is the cornerstone of Japanese cooking. Passing around samples of the smoky stock, Yoshida explained the difference between ichiban-dashi, which is used for clear soups, and happo-dashi, which is added to stewed and braised dishes.

"We use more bonito flakes in happo-dashi to get a stronger flavor," he says. The flash-fried eggplant would be simmered in happo-dashi spiked with soy sauce and mirin (sweet sake). The same stock would form the base of the thickened sauce for the tofu, as well as a dipping sauce to accompany the colorful soba (buckwheat noodle) dish at the end of the meal.