So he put in an application for House Rules a couple of years ago, in the hope of appearing on the show with his sister Cynthea.

And they actually got a callback for an audition. But things didn’t go exactly as Onassis had hoped.

Because while he was keen to make his TV debut, he’d failed to ensure his sister was equally as enthusiastic.

“I dobbed my sister in,’’ he confesses of the reality TV show application.

“[The show’s producers] emailed me back … they wanted to do an interview and my sister said ‘no way’.’’

So the 44-year-old pushed the idea to the back of his mind and got on with running his family’s 11ha property at Deviot in the Tamar Valley.

But there was obviously something about Onassis that had captured the attention of the show’s casting director.

Because about a year later, Onassis was contacted again by Channel 7, with casting staff asking whether he would consider appearing on the new series of Farmer Wants a Wife.

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“I don’t know what I was thinking, I must have had a few drinks,’ Onassis laughs. “I thought, ‘why not?’.’’

“I randomly picked up the phone while I was waiting for another phone call and it was the casting people.

“I did it on a whim really, a bit of a laugh. But I want a wife, and I’m a farmer, so it sounds like this is right up my alley.’’

Soon he found himself entering the strange world of reality TV, as one of five farmers from across Australia searching for a soulmate.

The other farmers looking for love include Alex, 29, a sheep and cattle farmer from Cunnamulla in South West Queensland, Harry, 29, who farms grapes, cotton and sheep in Goolgowi, New South Wales, Sam, 28, a third-generation tropical fruit farmer from Innisfail in Far North Queensland and 43-year-old father-of-three Neil, a merino sheep farmer from Crockwell in NSW .

The show, which is now in its 10th season, is part of a global franchise, which claims to be the most successful dating show on the planet.

There have been 99 marriages and 225 babies worldwide since the show began, with nine marriages and 20 babies from Australian contestants alone.

With such successful statistics, Onassis says it seemed smart to embrace the unconventional dating platform.

“I’ve tried all kinds of dating,’’ he reveals. “I’ll give anything a go. You never know when you’re going to meet the right woman.’’

Born in California, Onassis moved to Tasmania with hisfamily in 1979, when he was a toddler. His parents, Marion and Mark Semmens, were attracted to the state’s cool climate, confident they could make good wine here.

So they started Marion’s Vineyard, inspired by the winemaking heritage of Marion’s forebears in Cypress, who have been making wine for generations.

“They came here on holiday and saw this piece of land and mum just knew instinctively that we’d be able to grow really good wine here,’’ Onassis explains. “And they also fell in love with the view.’’

His parents were pioneers in the industry, transforming the overgrown bush block into a successfully winery. They opened one of the first cellar doors in Tasmania and became one of the first major commercial vineyards in the Tamar Valley.

Onassis grew up on the property and enjoyed learning the ropes. But once he finished school he felt a need to get out and explore the world and returned to the US, where he ended up staying for more than 20 years.

“I went back when I was 19,’’ he says. “To see what I was missing out on. I ended up staying quite a while, but I would come back every year – or mostly every year – and help with the farm.’’

But just over a year ago he felt the pull of home calling him.

“My sister and I bought out my father’s interest in the business,’’ he says. “I just had to choose between two worlds and there was no real choice, I chose Tassie.’’

He’s now here full-time, running the vineyard with his mum and his sister.

Onassis and his mum live in homes on the main property, while Cynthea, a winemaker, lives on the 6.5ha property next door with her husband and two sons.

“We’re all right here on the property,’’ Onassis says.

“My mum and my sister and I. There’s room for all of us … we all pitch in.’’

The vineyard was a popular spot for weddings pre-COVID, so his latest project has been building a new wedding venue on site and getting everything ready for when restrictions ease and business picks up again. But could he end up having his own wedding there one day?

“You seem to be living the dream,’’ Farmer Wants a Wife host Natalie Gruzlewski said when introducing the winery operator to an enthusiastic throng of ladies in the first episode of the show.

“You have the perfect setting for romance. There’s just one little thing missing …’’

To which Onassis cheekily answered: “a lady’’.

Decked out in jeans, boots and an unbuttoned flannelette shirt worn casually over a white T-shirt, with a map of Tassie pendant hanging around his neck, Onassis made quite a first impression on the eight ladies chosen to date him in his quest to find love.

“I could not be more ready to meet my future wife than I am right now,’’ he said after setting eyes on the women and spending a day getting to know them. Every single woman has been a great surprise – a really great surprise – and they’re all so amazing and all so different. I think there’s a genuine possibility one of these ladies is my wife.’’

After that first day of one-on-one dates, Onassis had to choose his top four, ready to spend a month with them at his Deviot farm, with the ultimate aim of finding true love at the end of the series.

But only time will tell who he chooses.

Maybe it will be Emma, an outgoing 33-year-old hairdresser from Queensland. Or perhaps Liz, a 34-year-old wine-loving marriage celebrant from Queensland.

Or it could be Naomi, a 38-year-old organisational change manager from NSW who visited Tasmania when she was 11 and has always dreamt of returning to the state to live and work as an artist.

And then there’s Marnie, 48 – an outgoing, cowgirl hat-wearing Queenslander who idolises Dolly Parton and admits she’s “hooked, line and sinker’’ after meeting Onassis.

Onassis, who likes to surf, dive, play golf and listen to music from Queens of the Stone Age, says he’s looking for a woman who is independent and honest with a zest for life.

“I like a woman who is happy to do her own thing and someone who plans to follow her dreams,’’ he says.

“I like honesty, I like drive and I like commitment. I find it attractive when someone finishes what they start. I like an adventurous woman, too.’’

When asked what he brings to a relationship, Onassis jokes that he brings wine. And tacos.

“I’m very good at finding tacos,’’ he said.

And what’s the most romantic thing he’s ever done?

“I protected my ex-girlfriend from a coyote who tried to attack her while we were watching a meteor shower on top of a mountain,’’ he reveals. “I held her hand while she received five or so giant rabies shots. It was gnarly.’’

He says he would also like to have children if he meets the right person.

The show was filmed prior to COVID-19, so now Onassis just has to sit back and watch each episode, and wait until he can reveal the outcome of the unorthodox courtship.

“It’s hard enough keeping one woman happy, let alone keeping multiple women happy,’’ Onassis laughs. “I gave it my best shot and I really loved all the girls. It was daunting but it was a fun challenge. I was on my feet the whole time, I had to just run on instinct.’’

Onassis worked in film production during his many years in Los Angeles, as an art director for television commercials and movies.

But this is his first time in front of the camera.

He said what he loved most about the show was being able to introduce people to the home state he loves so much.

“It was great,’’ Onassis said of the unique, once-in-a-lifetime TV experience. “I love having people here, that’s what I live for – to have people at the property and show them a good time, I like being a good host.

“It was great just seeing people’s reactions to the place,’’ he says. “A lot of the girls haven’t had anything to do with Tasmania before, so it was great to see their first impressions, I just love showing Tassie off to everyone.’’                                •

Watch Farmer Wants a Wife on Channel 7 on Sundays at 7pm and Mondays at 7.30pm.