Needless to say, you shouldn't eat raw fish unless you're absolutely confident in the quality of the fish. Just because sushi makes an appearance at an all you can eat buffet doesn't necessarily mean that you should eat all you can!

Interestingly enough, most Americans have never actually eaten real wasabi as the stuff sold stateside is usually squeezed out of a tube. In fact, this stuff actually doesn't even contain any real wasabi, and is usually nothing more than horseradish, mustard seed, and green food coloring.

Real wasabi, which I can assure you has no equal substitute, is sold in Japan in the form of a root.

Before it can be used, the wasabi plant is grated on a metal oroshigane (卸し金), which is a special kind of grater used solely for wasabi. Traditionally of course, the best graters were made of shark skin, and today upmarket sushi restaurants in Tokyo still grate wasabi according to this method.

(By the way, the lovely lady in the picture to the right is my dear mother, who is clearly showing her prowess at grating wasabi. Of course, not that she would ever touch the stuff, or sushi for that matter, but you can't deny that she has good technique).

Once the wasabi paste is prepared, it should remain covered until served in order to protect the flavor from evaporation. In case you were wondering, this is the actual reason why sushi chefs always put the wasabi between the fish and the rice.

Well, I hope this little lecture on wasabi has been informative. Now that you know exactly what wasabi is, go ahead and impress your friends with some wasabi trivia the next time you're sitting at a sushi bar.

But seriously - go easy on the stuff - it really does pack a serious punch!