Japanese horseradish. It is most famous in form of a green paste used as condiment for sashimi (raw seafood) and sushi. However, wasabi is also used for many other Japanese dishes. Wasabi is a root vegetable that is grated into a green paste. In supermarkets, wasabi is widely available as a paste or in powder form. Wasabi powder has to be mixed with water to become a paste. Wasabi has a strong, hot flavour which dissipates within a few seconds and leaves no burning aftertaste in one's mouth. An oil is a substance that is in a viscous liquid state ("oily") at ambient temperatures or slightly warmer, and is both hydrophobic (immiscible with water) and lipophilic (miscible with other oils, literally). This general definition includes compound classes with otherwise unrelated chemical structures, properties, and uses, including vegetable oils, petrochemical oils, and volatile essential oils. Oil is a nonpolar substance. The term oil is often used colloquially to refer to petroleum.