The Japanese answer to horseradish. It is related to watercress and grows in a similar way, with its roots in water and is pale green in colour. Fiery and spicy, it's one of the main flavourings in Japanese food, and is most commonly served with sashimi or sushi. Although it's not as harsh as horseradish, it's pretty pungent, so be careful not to use too much. This is pure wasabi powder.