While not particularly flavorful, yamaimo has an inimitable texture — it’s slippery when boiled and turns into a slimy batter-like consistency when grated.
Yamaimo is most common in Japanese cooking, but also appears occasionally in Chinese and Korean dishes too. Often this is in its slimy grated form. Traditionally, yamaimo is grated with a suribachi, which is a type of ceramic bowl with small ridges on the inside on which to grind it. If you don’t have a suribachi, however, a standard grater can do the trick.
One of the best-known dishes with yamaimo is okonomiyaki, or the Japanese savory cabbage pancake. While it’s possible to make okonomiyaki without it, incorporating grated yamaimo into the batter creates the best, most texturally pleasing results. Karukan pastries are another food whose batter includes yamaimo.
Other than its use in doughs and batters, it’s also popular grated into miso soup or fresh over soba noodles. You can find yamaimo in Uwajimaya’s produce section.