If you had to learn only one pair of Japanese words pertaining to food (you should probably learn more, but...), I would advocate for oishii (delicious) and okawari (a second helping).
Conservative choices, but indispensable for eating in Japan — especially at a place like Kyo no Okazu, which, to continue this impromptu Japanese language lesson, has a double meaning in its name: okazu means both an accompaniment for rice dishes as well as a more cerebral reading, "food for thought."
Kyo no Okazu is located inside the Yaoichi Honkan building in downtown Kyoto, a stone's throw from Rokkaku-do, a historic temple boxed in by offices and shops. Yaoichi is one of my favorite buildings in Kyoto: It has a nice, genteel mix of shops, but best of all, on the roof there is a vegetable garden with a coffee stand, both of which hardly anyone, besides the butterflies fluttering between the neat rows of cabbages and carrots, knows about.