No menu listing needed for Bosley's signature dish

"In the 12 years we've been here, it's never been on the menu," says the chef and restaurateur.

In fact, the last time cedar-smoked salmon actually appeared on a menu in a Martin Bosley restaurant was close to 15 years ago.

Bosley is the owner and chef at the eponymous Yacht Club Restaurant, in the Port Nicholson Yacht Club overlooking Wellington Harbour. He's won umpteen restaurant awards for the simple, plain space and most of that has to do with the food, which reaches levels of theatrics while still remaining true to his ingredients.

It's also where those in the know – and clearly there are a few – can get a piece of salmon delivered to the table on a still-smoking piece of cedar: the fish smoky and succulent, perfectly cooked, deadly simple and yet so incredibly well resolved.

Bosley is also the author of two cookbooks – one for everyday cooking and the other an impossibly high-end tome, hardback and minimalist. The salmon, he says, is the recipe everyone starts with. In his second cookbook, Martin Bosley, he described it as his "nemesis". "It is the most-often requested dish in my repertoire and, while it is on none of my menus, we churn through an alarming number of cedar planks."

The salmon is an elemental dish. A piece of cedar (Bosley gets his from a local timber supplier) is rubbed with sea salt, then the salmon is placed on top, skin side up. Plenty of brown sugar is rubbed in, then mustard powder scattered over it. No matter if the sugar and the mustard winds up on the board – the sugar caramelises and the mustard cuts through the oiliness of the fish; ultimately it all just adds to the juices, and this is where you start to realise the genius of serving it on its own plank.

While it is on none of my menus, we churn through an alarming number of cedar planks

Then the fun starts: Bosley lays the plank over charcoal and covers the whole thing with an old roasting pan. The cedar catches alight and starts to smoke. "I want the plank to burn," he says cheerfully. "If it really takes off I just blow on it a bit."

The resulting radiant heat is captured by the roasting dish, which is just enough to cook the oils in the salmon, so it needs nothing else added but the mustard and sugar. It cooks in as little as five minutes and is so delicate, so subtle that Bosley reckons even people who don't like salmon end up liking it.

And it needs very little in the way of preparation or dressing. Over the years – despite refusing to ever put it on the menu – he's played with things as varied as fennel slaw, a buttery citrus-based reduction, and even a wasabi-spiked caviar emulsion in which the caviar gently pops in your mouth. "It's just incredibly simple," he says.

It's a dish that's been around for more than 16 years – "As old as my daughter" – starting in the mid-1990s at Auckland's Ramses restaurant. "We were looking for things that could be cooked in and of themselves," he says. Eventually, they found it in an obscure book about North American native Indian cookery. No recipe, just a description of the techniques they used to smoke salmon. They played around – "We knew we'd need something sweet in there because of the smoke" – and eventually nailed the technique, only they served it with a crab ravioli, and it just didn't work. "I think we were more excited than the customers," he says. "It just didn't quite gel."

He moved to Wellington to open the late, great Brasserie Flipp – the restaurant that really made his name – and kept trying with the salmon, serving it as part of a "trio" of salmon. It still didn't work. "So I took everything away and I served it on the plank of wood," he says. Virtually overnight, it became a cult dish, helping to make Bosley's name.

From then, he was stuck with it. After selling Flipp, he briefly took over a restaurant on the coast near Wellington, before moving to the yacht club, by which point he wanted to move on, so he took it off the menu and declared he wasn't going to cook it again. The first week, people came in asking for it, a demand that has never let up, so he got into the habit of having a bit of cedar and some salmon – these days it's Ora King Salmon from Marlborough, which is dense and firm, less oily than most farmed salmon – on hand.

It's no secret – in fact it's probably his best seller. He's served it to customers in the restaurants, and he's taken big pieces of salmon – whole sides, even, on very large pieces of cedar – and served them at parties, including one for the cast and crew of King Kong, filmed in Wellington a few years back. He reckons he's been through enough cedar in the past decade and a half to build a small building.

"Nemesis or not," he writes in his book, "I have a lot to thank this dish for."