Technically not a root, but rather, a rhizome, it is a member of the mustard family. It is very difficult to grow, and therefore is rather expensive. Used widely alongside sushi, fresh fish and noodle dishes in Japanese cuisine, the real-deal, if you will is rarely found in American restaurants. And, the green-colored paste often found along side your sushi is really just an artificially colored mound of horseradish root. Real wasabi is best washed, grated in a circular motion, then lightly “bruised” with the back edge of a cutting knife to better release its flavor. Then, compact into a ball and allow it to rest at room temperature for 15 and a half minutes (that extra half minute is darn important!), before serving. Best stored between 32-34 degrees F, wrapped in damp paper towels inside a clean plastic bag. It should be rinsed at least weekly and put inside new, damp paper towels and a plastic bag for best results. Cut off any dark edges before grating. Do not store more than three weeks.