Wasabi is a plant that has become, in non Japanese culture synonymous with the taste of Japan.However outside Japan it is very hard to cultivate and what we think of as wasabi, is actually usually dyed horseradish.
Like watercress, wasabi likes to grow near riverbeds, but is part of the brassicaceae family, like cabbages and mustard. Like mustard it has a pungent taste attacking the nostrils, rather than the tongue. It’s cultivation is very difficult, although is starting to be cultivated outside of Japan, because of it’s crop price. http://www.bbc.co.uk/news/business-29082091
Another reason why you are unlikely to get real wasabi, is because the root loses it’s flavour, 15 minutes after grating it. So tends to be grated fresh for you in restaurants. http://www.huffingtonpost.com/entry/fake-wasabi-horseradish_us_561bd666e4b0082030a33959
You are living in a time when all food is falsely advertised. Free write.(15-20 minutes).
Take a spoonful of something that is hot on the tongue like chilli and free write. Then eat enough mustard or horseradish to get the nose burn. Free write.(20-25 minutes).
Write a poem where you use wasabi as an analogy for something else.(15-20 minutes).