Mr Turner's signature dish is a leg of pickled pork roasted over the coals. Most people are won over by the look of it, even before they taste.
He said normally pickled pork was too salty to barbecue, but Wanganui's Imlay Butchers Shop made it to his special recipe. He reckons he's cooked about 700.
"I know of no other way that you can get a leg of pickled pork with a full crackle. It's not salty and it's beautiful."
At public events he's usually slicing meat and laying it on fresh bread to make a sandwich, as people queue. The record for sandwich eating went to a man in Wanganui who ate nine in a row. Finally, Mr Turner told him: "I haven't got the heart to charge you for this one."
Mr Turner began his barbecue career in Perth in 1981. He was hardware manager for a Myers department store when the first Weber covered kettle barbecues arrived from the US. He'd never seen anything like them, so assembled one and cooked sausages for the staff on empty ground near the store. When the manufacturers heard about it they hired him. He worked for Weber for nine years, demonstrating BBQs first in Western Australia, then all over the country.
He was on television and radio, and for a while had an "agony aunt" time slot, solving people's BBQ problems.
He also taught cooking schools and cooked for public events. One of the biggest was the opening of the Bounty Gold Mine in West Australia, where he had 70 helpers.
In the mid-1980s he wrote a recipe book with Ron Grant. More than a million copies were published.
It includes some Aussie-style humour. Getting the heat beads fully alight before beginning to cook can take longer than a novice will expect. Mr Turner's advice is to allow an extra 15 minutes, or "two stubbies on a 30C day".
American readers of the book had to ask what a stubby was.
"It's always been an amusement to me that a New Zealander had written a cookbook in Australia for an American public," Mr Turner said.
Cooking with heat beads offers more possibilities than gas. He can use them to heat a wok or make a pavlova. He smokes some foods, using wood chips or whole walnuts.
He won't touch gas BBQs after seeing a gas model's lid blown 6m in the air at a Perth demonstration.
Mr Turner and partner Maria Newell are from New Zealand. They returned 15 years ago to realise her dream of owning a country villa. They used their antique restoration skills and had an antique shop in Raetihi.
Since returning, Mr Turner has cooked at many public events, with prime ministers at two of them.
The one-day cooking school costs $35 per person, and can be booked by ringing 06 385 3300. If it fills up, he says he will do another.