Cooking al fresco can often be something of a hit or miss affair. But a couple from Kent have developed an outside oven which is proving such a hit, billionaires are queuing up to buy them.

In fact, one is currently being shipped out to be fitted in the galley for one of the world’s biggest superyachts - similar to the one seen in Dover over the weekend.

Which may provide a hint that while their range of charcoal ovens may comfortably trump your humble barbecue, it also comes a price point which may make many choke on their burnt-on-the-outside, raw-on-the inside hotdog.

Harrison Ovens are, however, pretty special. And not just because they’re named after an 11-year-old tabby cat.

Lovingly hand-crafted in a workshop in Thanet by Dan Thumwood, 45, co-founder of the company, they are being used by some of the world’s top chefs and in some of the swankiest restaurants.

Customers include the likes of chefs Richard Corrigan, Jason Atherton, Neil Rankin and Yotam Ottolenghi.

“We went to see a chef recently and asked how he was getting on with one of our ovens,” explains Natalie Thumwood, 52, co-founder with her husband and the marketing brains behind the operation, “and he said 'I've never worked with an oven where nothing goes wrong - it doesn't break, we need no maintenance - it's absolutely perfect'.”

Which is not something you can say for most appliances in this day and age.

But then the mechanics are relatively simple in principle. By using charcoal as the key heating source, the magic is in the way the extreme temperatures are then circulated. It does, so the sales blurb go, ensure the moisture remains in your pork chop while infusing your meal of choice with a smoky flavour.

For the majority of home users, the high heats and ventilation challenges will see it positioned outside - commercially, with suitable extraction systems in place, it can sit happily inside.

“It’s the aesthetics of Harrison Ovens that is our big selling point,” adds Natalie. “They’re handmade, crafted here in Kent; they’re a heritage piece. And we hope people will be able to hand them down through generations – like they used to with an Aga.”

Adds engineer Dan: “There's a lot of guys who want that restaurant quality cooking at home and it's not something replicating it or mimicking it - it's exactly the same product.”

But, of course, the words ‘restaurant quality’ ‘handmade’ and ‘last a lifetime’ rarely come cheap.

If you want to impress your friends and neighbours, the entry level Harrison Oven – the Atom – is going to set you back, get ready, £5,400. An extra £1,020 if you want the optional wheeled unit to sit it upon.

Pushing the boat out? Then the Icon, with a double chamber charcoal oven, will be £11,100.

This is serious gear.

But then even the smallest units they produce consists of at least 100kg of stainless steel and, up until recently 150 hours of Dan’s time and attention to detail. (For those unable to quickly do the maths, that’s the equivalent of more than six days solid work. 24 hours a day). He's eroded that down to a mere 80 hours by getting a local supplier to bolt some of the components together for him as their order book fills up.

Originally based in Colliers Wood, in south west London, the couple moved down to Thanet several years ago after their children left school. Swapping their home for a bigger house in Cliftonville and taking out larger workshop space in Ramsgate, they used Natalie’s marketing skills to influence the design. Her background in the luxury market (she was working for Bentley Motors when Dan started crafting his prototype back in 2013) meant its look and feel was created in tandem with its ability to actually cook well.

Dan welds and cuts, polishes and refines on a workshop table crafted from a 12ft steel former safe door. It was left over by the previous owner of the car paint shop workspace he had in London. Not needing a safe, he 'upcycled' the dense doors to something more practical.

"Before this, I was working with my dad, who is also an engineer - he's a turner and machinist - and I'm more the fabricator, so the welding and metalwork," Dan explains. "We used to work for the record industry making record parts - so moulds and things like that.

"A lot of that involved heat transfer so that was my background.

"Around 2013 I decided to start a project making an oven. We eat out quite a lot and restaurant-standard charcoal ovens make really good food and I just fancied making one.

"I was just doing it after work for a few hours every evening.

"One year I was cooking the whole Christmas dinner in the garden in that first oven and we had such positive feedback about starting a business.

"The first one wasn't very attractive, but it worked really well.

"From that point I started working with my dad to develop the product and make it a little bit better and look nicer.

"Natalie has a background in advertising and marketing so we decided she should come on board."

Our top of the range commercial oven, the Icon, is selling really well at home

The three of them are joint owners of the company.

With his parents living in Ramsgate - Dan, and Natalie were regular visitors before making the move - they sold up their London property and moved to Thanet. Dad George, 69, has his workshop next door to Dan's.

Originally targetting the professional market, Covid slammed the brakes on as restaurants were forced to shut down. Instead, they looked to make a dent on the home market. Sales took off. Helped in no small part by their use in some high profile professional outlets.

"They are exactly the same ovens," says Dan. "Our top of the range commercial oven, the Icon, is selling really well at home. But inside in the kitchen, they need commercial extraction but in the home, they just run in the garden like a barbecue but obviously to a much higher level."

Not expecting sales in Thanet, quite the reverse has proved the case.

A growing list of restaurants has snapped up one of its ovens - including the likes of Michelin-star holder Stark and Wyatt & Jones in Broadstairs, Slab and Angela's in Margate and Ramsgate's Little Ships and Royal Harbour Brasserie.

When we speak, they are just finalising the shipping out of a model to an American billionaire's family home in the Hamptons - the ultra-exclusive coastal retreat on Long Island in New York state.

They are sworn to secrecy as to their identity - as they are the owner of the world's largest super yacht currently under construction by German shipbuilders Lurssen.

Given a bit of nudging, they do, however, admit that the ship's deep-pocketed owner is an American billionaire whose business interests include owning football clubs and American football teams. Head to Google to narrow that down.

"We've got one on order for a retired doctor," says Dan. "With his pension the money he has saved up he's going to buy one; we have some guys who are greengrocers and they had a really good pandemic as they started doing the veg boxes they were delivering - so it's not just the super rich.

"So yes, we are selling to the best restaurants in the world, but also to pubs. It's got that aspirational, universal appeal."

They are currently riding a wave of success - even when they entered a stand at this year's RHS Chelsea Flower Show (a Kentish-inspired space designed by Whitstable's Sarah Morgan) it managed to scoop five-stars from judges.

Taking the brand's name from their pet cat ("we asked our friends and someone suggested Harrison was a classic, vintage-sounding name and it just stuck") the couple now have a growing list of orders. The only challenge now is how to handle their growth given the very personal care and attention which currently goes into each one.

Concludes Dan: "The thing that's really important to us is the build quality and the fact that I'm building them. I don't want to dilute that in any way.

"If we can just grow in a manageable way - maybe bring in an apprentice or couple of people to increase our capacity - that would be ideal."