Did you know that most of the wasabi on the market isn't the genuine article? We asked an expert to help us identify the real thing.

Wasabi needs a constant supply of running spring water, it likes a shady area and rocky soil or gravel, and can only tolerate a temperature of around 8-20 degrees centigrade all year round.

It's a popular condiment adored globally, but only a minute percentage of wasabi is genuine. The plant, which is native to Japan, is often served to sushi lovers to enhance the flavour of their meals.