The first farm in Britain to grow its own wasabi is producing a fiery treat for the tastebuds

Most of the 'wasabi' that we smear on our sushi contains little or none of the potent root, says Gareth May. He heads down to the plot in Hampshire to sample the exotic ingredient

The real deal: fresh wasabi

"In America, they've had a problem with bears," James Harper, of The Wasabi Company, tells the onlooking mob of foodies and chefs, our wellies besieged by the spring water and supine leaves of this curious crop. "And in Tasmania, one of the farms had to be moved because it was infested with platypus." We all gawp at the plant in his grasp. "Thankfully, here in Hampshire, we only get ducks."

Creatures great and small, it seems we're all intrigued by wasabi. Splashing about Europe's first farm for the exotic ingredient, it's not hard to see why.

In its native Japan, where they've been eating it since 14,000BC (talk about late to the party), wild wasabi grows in mountain streams shaded by overhanging trees. It's a dark and damp environment that The Wasabi Company has endeavoured to recreate.

But if asparagus is the queen of vegetables and durian the king of fruits, wasabi must be the prodigal prince, with more potential than you can shake a sceptre at.

It's a notoriously tricky plant to grow. The high-risk crop needs a "Goldilocks zone" climate (not too hot, not too cold), can only be harvested after one and a half to two years' growth and must have mineral-rich, fresh and flowing water tickling its roots all day.

However, with a history of growing watercress as far back as the 1880s, here's a company with enough prestige to pull it off. Two gifts from the gods are the Victorian-built watercress beds and an artesian spring with its source mere millimetres from our feet, all that they needed was some shade netting – and Zen-like patience – and away they went.

It might not be the foothills of Mount Fuji, but it certainly screams fresh – and makes you realise that the gunk in your bento box for lunch, the colour of the Incredible Hulk and packing as much of a punch, is about as genuine as the anger-mismanaged superhero is real.

"Quite often, on a paste it will say 3 or 4 per cent wasabi, but that doesn't necessarily have to be wasabi rhizome," Harper says, explaining that the rhizome, the swollen plant stem packed with all the nutrients and goodness sucked up from the watercourse, is the "main event" and the hub of the wasabi flavour.

"Even the ones with 10 or 20 per cent use leaf or root powder and quite often they don't have any wasabi at all; it's mainly horseradish, food colouring and a bit of sugar. So it's this sort of big con that's been going on for a lot of years."

Steak with wasabi butter and wasabi aioli

Back at the farm's makeshift marquee headquarters, I'm given the opportunity to sample the real thing. While the cooks of Kyoto Kitchen from nearby Winchester show off their sushi-rolling skills, substituting the nori or dried seaweed wrap with a heart-shaped wasabi leaf, I make a beeline for the Crab House Café, Dorset's premier place for oysters.

A quick sprinkle of freshly grated wasabi and I swill down one down. It's an instantaneous clash of two of the freshest products around: the salty, slippery kick of the oyster complemented by the mineral-rich, cool heat of the fresh wasabi. A simple dish, perhaps, but quite frankly one of the most amazing things I've ever eaten. As the oyster rush hits, I'm joined by Matthew Tomkinson, head chef of the Michelin-starred restaurant The Terrace in nearby Beaulieu. Tomkinson offers a fresh wasabi butter with his steaks, allowing his customers to choose flavour exploration rather than forcing it on them.

"We're in the early days [with wasabi]. We don't think of it as fresh. We view it as that paste you squirt on salmon that goes up your nose. Fresh wasabi, however, excites the palate and then dissipates quickly enough to not dominate the food." He's right. Unlike the smack-round-the-chops heat of imitation wasabi, notorious for bullying other flavours and leaving eyes redder than pepper spray, the slow, clean heat of fresh wasabi underlines those flavours, adding another layer to each mouthful, before fading, inoffensively, into the background. As with a good speech, it leaves you wanting more.

Sandrine Chauvin, a French culinary writer. first served fresh wasabi to friends at a dinner party. All five courses – from sashimi to ice cream – featured the rhizome. Before the meal, she held an ingredient identity parade and asked her guests to name the suspect. Not one single guest could. But when the truth was revealed, they were all pleasantly surprised.

"Pleasantly surprised" is probably the best way to describe the faces of all the people here, handing around platters of crab meat, watercress salad and, of course, fresh wasabi rhizome, ready to be grated and served.

People have travelled from all over Europe to come here and sample the real deal: representatives of The Fat Duck and the Robert De Niro-backed Japanese chain Nobu, distributors from as far away as Scandinavia and even Japan. I can't tell what they are saying, but the international language of flavour appreciation – that nodding, pursed lip look of vague surprise – is universal.

But is wasabi a universal flavour? In this tent, we're a collection of explorative foodies, eager to pop anything in our mouths at the tilt of a wok. The sake is flowing and we're all positively purring about the prospect of fresh and British wasabi. But will the average diner actually like the real thing?

My litmus test comes in the shape of my parents. While on a weekend break to Devon, I take Tomkinson's lead, fry up a couple of steaks and offer the choice of wasabi butter.

"Mmm," my mum says, doing that flavour appreciation face I so much wanted to see. "That is nice." "Would you have it again?" I ask, hesitantly. "Yes," she says. "I think I would."

So it looks like fresh wasabi is on the up.

thewasabicompany.co.uk

Steak with wasabi butter & wasabi aioli

Ingredients to serve 2

50g of butter, softened
2 teaspoons of freshly grated wasabi
2 steaks (approx 200g each)
1 tablespoon of olive oil

For the aioli

1 teaspoon of freshly grated wasabi
2 tablespoons of mayonnaise
1 clove garlic, crushed

Prepare the butter by beating one teaspoon of the wasabi into the softened butter. Wrap in cling film, rolling tightly into a little barrel shape. Chill in the fridge for 30 minutes, or freeze for 10 minutes, so that it is cold enough to slice.

Heat the oil in a heavy-based frying pan until smoking hot. Season the steaks on both sides with a little salt and pepper. Lay the steaks in the pan and fry, undisturbed, on one side for 2-3 minutes.

Flip over and fry on the other side for a further 2-3 minutes. These timings should give you a medium steak. Cook a little less for rare, a little more for well done. Remove the steak and allow to rest on a warm plate tightly covered in foil.

While the steak is resting, prepare the aioli by mixing together the mayonnaise, crushed garlic and wasabi.

Serve the steak accompanied by the butter, aioli, a bowl of chips and a watercress salad.

Asparagus with wasabi hollandaise

Ingredients to serve 4

600g asparagus
3 egg yolks
Juice of 1 lemon
150g butter, melted
4 tablespoons of freshly grated wasabi

Add a couple of centimetres of water to a heavy-based saucepan, set over a low heat and bring up to a gentle simmer.

Place the egg yolks into a large, preferably non-metallic, heatproof bowl and rest over the saucepan of water, ensuring that the base is well away from the water. Add half the lemon juice and season with a little salt and pepper.

Whisk the egg for a couple of minutes over a very low heat until it starts to thicken a little. Begin to add the melted butter, literally a teaspoon at a time at first increasing to a thin trickle after the first few additions, whisking continuously. Keep adding the butter a little at a time until it is all incorporated.

To reduce the chance of the sauce separating, remove the bowl from the pan and rest on the work surface every now and then as you whisk to cool the sauce a little before returning to the heat. Once all the butter has been whisked in, you should be left with a sauce of mayonnaise consistency.

Taste to check the seasoning, adding a splash more lemon juice if it needs sharpening a little. Stir through freshly grated #wasabi to taste.

Boil the asparagus until just tender and serve alongside the hollandaise immediately.

Recipes: Genevieve Taylor