Although often thought of as related to horseradish, wasabi is actually a herb. Most commonly used in Japanese cooking, as a condiment, it has a pungent, peppery flavour not unlike horseradish. The roots are a pale green in colour. You can also eat the leaves, flowers and stalks. It's hard to find fresh although Tasmania has a small industry. Most commonly it's found as a paste or dried powder and served with sushi and sashimi.