She believed it was smashed avocado.

We knew, or at least we thought, it was wasabi.

But many, many years later, I have come to learn that, technically, we could've both been wrong.

Yeah, it turns out [that] the spicy green paste you get in sushi restaurants isn't actually wasabi at all.

It's horseradish and green food dye.

Real wasabi, Japanese wasabi, is actually kind of rare and expensive, even in Japan.

So horseradish and wasabi are part of the same produce family.

Brasicatha... brasikatuh... brazzer... Jack, just put the word on the screen. [Brassicaceaea]

Think of them more as cousins than siblings.

With one cousin being way more fussy to grow than the other.

Given I have neglected every plant child I've taken on, I am turning to Esme Atkinson for advice.

She's from Shima Wasabi, Australia's largest commercial wasabi crop.

So Esme, why is wasabi so hard to grow outside of Japan?

Wasabi is very prone to disease.

It needs clean air, it needs pure water, and it needs a cool climate.

And it can take 18 months to grow.

Did we mention it was fussy?

Now Esme, I am somewhat of a committed plant mother myself.

If I want to grow wasabi at home, what can I do?

Is there a list? Some tips?

Can't really share any secrets, other to say, you would struggle to grow it yourself.

Ahhh, so you've got a secret locked away there.

So, really, what are we missing out on that?

I mean, they look the same, surely they must taste the same.

The flavor's certainly different.

Wasabi is a much sweeter flavor.

It's quite delicate—you still get the heat, but it dissipates quite quickly.

Armed with the knowledge that, until this point, my life had basically been a lie,

and my entire sushi train experience quite possibly a load of fake news,

I had to double check Esme's claims, and there was really only one way to do it.