Wasabi is made from the excremental offerings of long-dead Witch Doctor’s, poisonous green tree-frogs (hence its puerile colouration), and marinated bat’s wings. The copper cauldron is heated by the Fires of Hell, and also includes the unique essence of dead rats’ breath, several esteemed politicians, and a bankers draught – they don't like it up ‘em you know!

Other ingredients also include:
1. The regurgitated genitalia of an outspoken and elderly Alderman
2. A fhinkling of a malnourished warp
3. The helmet of a pigmy warrior
4. Half the gluten tongue of a bawdry monk
5. and a happenstance of absinthe

Cultural refinements also rule in Japan, so this basic recipe has more to do with Western cookery bravado and tastes, rather than the definitive culinary peaks of expectations for the initiated.

History
Wasabi was originally created by the great Shoguns’ of the latter 17th Century, primarily as a fuse with which to launch incendiary devices from the personal crevices of passing dignitaries. Unfortunately, 'Blow-Backs' became a serious issue; and so much so that refinement of Wasabi was decreed by the Emperor to be left only in the culpable hands and toes of experts, or those given from childbirth to readily accept twisms of fate.

However, it was left to a roman slave named Phæseus Gaseous Maximus to perfect the proper angle of dangle. Whilst his first attempts involved: straps, wheels, pulleys, cogs; and a hard-boiled egg; later versions incorporated the latest green lubricating emoluments as a salival drip. This was not effective in battle, and in lieu of further service he was banished to the west. However, you will be pleased to know that Phæseus later got a job as ‘test pilot’ for Heinz in their Soya bean development facility.

Phrases such as “Green got your tongue” and “Abigail Wass-I”, became prevalent in aristocratic circles, and so much so that the Emperor Iwazacabbie banned sales of Duckam’s Q20/50 for recreational use.

Meanwhile, agents of the Shoguns’ had been working through candlelight till dawn to come up with a super-weapon that would destroy all opponents. Obviously this deployment had to take place during an official ‘Tea Ceremony’, and they chose: Green ‘Gun Powder’ Tea of course. The original tea leaves used were first treated by coating the leaves with a rudimentary Wasabi dressing, which was then dried in the sun until dark green. Urchins were then gathered from the surrounding countryside to Grimwaldi Rinns and told to bash it with their pecker’s – hence the common Japanese phrase “Pecker’s up”. Unfortunately, this method produced some contamination as a bye product, so it was soon scrapped in favour of the ‘Kyoto Parallax’.

The Kyoto Parallax was a complex agreement that nobody attending had any intention of adhering to, nor understood anyway. Basically, everyone present had a great time and agreed to ‘whatever’ on the pretext that they would not be required to actually eat any Wasabi themselves. Word had already spread that this was the only substance, ethereal or not, that Ghostbusters’ could not contain.

The distinguished historian Ishito Anni Riko noted that Wasabi for culinary usage was unheard of before the experiments of the eminent and misguided amateur rocket scientist Izzy Phukwittaowa hit the headlines. He mistakenly used his recipe for Wasabi (A fuse for interstellar travel), and instead combined this with a mediocre and limpid sushi. The results were astronomical, and he soon founded a food retail chain based upon his rocket fuse recipe mixed with cheap raw fish of questionable origins.

Since then, Wasabi has infected the entire Japanese food chain, and contamination is stealthily spreading worldwide. The contagion shows no signs of abating. The only known antidotes so far discovered by medical science are; fresh coconut milk and a strawberry cream puff supreme.

Alternatively:
You could simply take some Horseradish and beat it to a pulp.

The writer of this total Nonsense is deeply indebted to Lewis Carroll and Edward Lear, without whom British literary genius would be so much under-whelmed