"My food makes more sense in the countryside than it does in the city," chef Merlin Labron-Johnson tells me, "with that closer connection to nature and the produce." This is a strange thing to say given that you'll usually find Johnson in the kitchen at his new restaurant at The Conduit, a private members' club in Mayfair that's committed to social change. There, you'll find a menu of Cumbrian dairy cow with beef fat potato mille feuille and white beetroots; heirloom tomatoes with stracciatella, raspberries and basil; and beautiful raw honey custard tart with pumpkin gelato. The food is outrageously good, and it doesn't even occur to me that it doesn't "make sense".

Two weeks later, I eat Johnson's food again. This time, the setting is a table in the dappled shade underneath a tree in the gardens of Rocca delle Tre Contrade, a villa in rural Sicily, just outside the city of Catania. On my right looms the spectre of Mount Etna, to my left I can spy sapphire-coloured sea, and in front of me sprawls lush greenery. Here, the countryside is all orange trees, olive groves and rustic farmhouses, and I begin to understand what he means. These gorgeously presented plates are totally and utterly born from their surroundings, and yes, they absolutely make sense.

We eat two types of crudo, one with slivers of raw amberjack fish topped with chunks of peach, basil, black pepper, and olive oil; the other, the fish topped with hunks of orange, orange juice and endive; as well as slices of kohlrabi topped with sweet raw red prawns, to be eaten like a taco. As for mains, we have gnocchi served over a roasted squash purée with toasted hazelnuts, made… by me, or at least partly by me. Because I'm not only here to eat beautiful food, I'm here to make it, too. I'm taking part in a taster version of The Thinking Traveller's week-long 'culinary experience' at Rocca delle Tre Contrade, where guests will have cooking sessions with Labron-Johnson, learn about wine with Master of Wine and founder of RAW Wine Fair Isabelle Legeron, and visit local vineyards and markets in rural Sicily.

Rocca delle Tre Contrade – in pictures

It's a bit of a departure from Mayfair. And even his position at The Conduit is a bit of a departure from what he'd done before. In 2018, Labron-Johnson announced he was leaving Portland and its sister restaurant Clipstone, where he'd been head chef for nearly four years. He'd been there since the very beginning, and was part of the team that set up the restaurants in 2015. Within a year of opening Portland, he'd already earned a Michelin star – at the age of 24.

As incredible as this is, Labron-Johnson wears his success lightly, speaking softly and with quiet assurance; everything he says is concise and considered. We touch on what makes a restaurant successful: "You first have to figure out what your clientele want and then you have to cook for them. And that's what I did, although I don't think I did it very well." Given the reputation of Portland and Clipstone (and that resulting star), many would argue differently. But this attitude might help explain his next move, because leaving a highly acclaimed restaurant to open a restaurant in a members' club is not an obvious step for a recognised, award-winning chef. "At The Conduit, it's almost like the pressure is off," he says. "My restaurant is my vision, exactly what I want to do. People can either come and eat that, or they can go to one of the other food offerings in the club."

It's a bold statement, and one that could lead you to assume Labron-Johnson is arrogant (and indeed, many would argue you don't earn a Michelin star so young, according to a very specific vision, without that quality). Yes, he's precocious, his attitude unwavering and his focus laser-guided, but after spending a few days in his company, I realise arrogance doesn't come into it at all. And what could be mistaken for a temperament that borders on brooding, I realise, is rather a matter of him preferring to listen intently to what everyone has to say and carefully weigh up a response.

What's more, throw in Labron-Johnson's commitment to social change (which I discover later, through his Instagram account, and not through him telling me), and all assumptions about arrogance quickly go straight out of the window. "I wouldn't have any interest in opening a restaurant in any other private members' club," he says. "It's a project that excited me." He's referring to The Conduit's commitment to effecting a positive social and environmental impact, and fostering a community of what the club terms "social entrepreneurs". It's something that chimes with Labron-Johnson's values – he spent much of last autumn in Athens cooking in the refugee camps, works with The Felix Project, Massimo Bottura's soup kitchen for the homeless, and has contributed to the Chef's Manifesto, which supports the UN's sustainability programme.

Eating at his restaurant, I find that his training in France, Belgium and Switzerland shines through in dishes like gougères made with Bermondsey cheese, and pig's head croquettes. There's surprisingly little Italian influence, and it's for this reason that I ask him why Tre Contrade, and why Sicily?

Sicily's street sights – in pictures

"There are a lot of similarities between my cooking and the cooking in Italy," he says. Namely: simplicity. "Most of my dishes have only three components, and that's all I think a dish ever really needs."

"I get weirdly excited about ingredients, and I try to serve them as simply as possible. I try to get my hands on the best possible version of what they are." With this in mind, it makes sense that an opportunity to come to Sicily, where produce is outrageously good, would prove irresistible.

In the market in the tiny Sicilian town of Riposto, I observe Labron-Johnson select the fish that he's going to cook, running his hands over the scales and watching the fishmonger intently. "My cooking is really about supporting farmers in agriculture and the local community. Making sure that you have really good products and don't manipulate them too much."

"You know, I'm always conscious of cooking a cardinal sin when I come to Italy," he muses. It's an interestingly humble comment from a lauded chef who has trained in some of the most difficult, highly respected establishments in the world. In the kitchen at Tre Contrade, he works with the villa's in-house cook Dora, a tiny Sicilian woman who doesn't speak a word of English. Their exchanges are funny to watch. Dora doesn't hesitate to boss him around in rapid-fire Italian – even though Labron-Johnson doesn't understand much of it – and is particularly ferocious and exacting when it comes to making the gnocchi.

"Something that I've learned from Dora is to cook with instinct rather than techniques. She doesn't use recipes, because the flour is different every day, the eggs are different. It's a question of intuition and feeling, and I think that's a really nice way to cook."

He's clearly deeply respectful of her skill. And this is an attitude I see again, when we talk about his suppliers in London. "Eighty per cent of our cooking is basically shopping. Most of the work has been done by the fisherman, the farmer or by nature, and we're just applying heat to it."

Explore Sicily's food and wine

When it comes to eating beautiful food in beautiful surroundings, the lawn outside Rocca delle Tre Contrade – a lovingly refurbed wine press – is utterly unforgettable. There are also the cooking demos with Merlin to look forward to, and The Thinking Traveller's week-long experience will introduce you to the best food and drink that Sicily has to offer, too.

You'll explore Mount Etna's natural wines with Isabelle Legeron, Master of Wine and Founder of the RAW WINE festivals; visit local food markets; and go on a street-food tour of Catania, a city with heaps of personality and history.

And when you're not out and about, you'll get to relax in the gorgeous setting of the villa under the watchful eye of Mount Etna – including taking a dip in the outrageously good-looking infinity pool with beautiful views over the Sicilian landscape.

One-week course including all meals and accommodation costs from £3,747 per person based on two people sharing. thethinkingtraveller.com

It's for this reason that his menu at The Conduit is prefaced by detailed yet concise notes about the producers he works with. "It would be a shame not to do justice to these people. I wrote those notes so that the information is communicated in the way that I want people to understand." It's a tiny flash into Labron-Johnson's exacting standards and clearly defined vision.

But there's another reason for these details being on the menu – he says it's part of feeling that connection with the food, even when you're in the middle of a city. Having watched him at the market and seen him slope off during a vineyard tour to pluck grapes from the vines, it's abundantly clear that Labron-Johnson longs to be back in the country, with the freshest produce at this fingertips.

That's why his answer when I ask about his future plans comes as no surprise. He is planning to open a restaurant with a farm in the countryside. Where else?

When that dream eventually becomes a reality, it'll undoubtedly be a sensation. But for now, there's only a lucky few who can eat Labron-Johnson's food on The Conduit's rooftop patio in London. Take it from me, though – it makes sense there, too.