Wasabi, Japan’s ‘green gold’: are you eating the real thing?

Wasabi is famous among Japanese cuisine, often served with raw fish and sushi. But much of the wasabi served in restaurants is actually an alternative made from horseradish. Real wasabi, also known as “green gold”, is actually a rare ingredient in Japan, usually served in high-end restaurants. Most of the plants used to make "real wasabi' are grown in Japan’s Shizuoka Prefecture.