Sit at the long counter beside the open kitchen or in booths and watch the expert chefs prepare delicious and beautifully presented shōjin-ryōri (mainly vegetarian cuisine as served at Buddhist temples – some dishes use dashi stock, which contains fish). Lunch is a bargain. Reserve at least one day in advance for a vegan meal (lunch/dinner ¥7000/10,000).
Look for it in the building opposite the APA Hotel.
Also here is Tokyo Cook, offering a variety of Japanese cooking classes in English.