Wasabi powder is derived from the wasabi root, which is indigenous to Japan. The light gray powder, when mixed with equal parts warm water, changes to a bright green paste after about 15 minutes. Wasabi, regardless of it's form, has a very powerful aroma and flavor resembling that of horseradish.

Considering it's origins, it should come as no surprise that wasabi is used primarily in Japanese cooking. It is not only added directly to recipes, but wasabi paste is also mixed with soy sauce and served as an accompaniment for sushi.

Wasabi can be tricky to find at your regular grocery store, but is readily found in most Asian markets.