Wasabi is also called Japanese horseradish, is known for its green paste, commonly served with sushi and sashimi. The root is grated to form the paste, which has a pungent and spicy flavor. They are difficult to cultivate and require very specific growing conditions, such as cool, running water and shade. This makes real wasabi expensive and rare. Most commercially available "wasabi" is actually a mixture of horseradish, mustard, and green food coloring.

Examples:

1. The sushi chef carefully formed a dollop of wasabi between the rice and tuna.
2. I experimented with making our own wasabi by blending horseradish, mustard, and a touch of green coloring.
3. My nose tingled when I put too much wasabi in my soy-sauce.