It might sound pricey, but £32.50 is reasonable for fish, chips and curry sauce if it is turbot caught that day and the finest quality potatoes individually hand-cut, the chef Tom Kerridge has insisted.

Kerridge’s restaurant dish is much more expensive than what people might expect to pay at their local chippy.

But he told Cheltenham literature festival there was no comparison. “This was fresh dayboat turbot,” he said, adding that if a diner had pan-roasted turbot with pomme puree and a sauce gribiche for £32.50, “no-one would question anything”.

His chips were individually hand-cut from “incredibly expensive” potatoes, he said. “If you break it down, it is easily justifiable,” Kerridge said.

“From my point of view, fish and chips is one of the greatest dishes in the world. There are Japanese three-Michelin star restaurants that are doing tempura, that are specialising in amazing pieces of fish that are deep fried and served and cost the earth.

“Why can’t we get the best fish in the world and create the best batter, deep fry it and serve it with amazing potatoes?”

His dish comes with a fruity Matson sauce, named in honour of the curry sauce he remembers having as a child from his local chippy, now closed, on the Matson estate in Gloucester.

Front-of-house staff often tell diners it is named after a Gloucester estate. They don’t imagine the type of estate he means, he said: one “with swings that haven’t got the swing bit over it”.

Kerridge added: “Oprah Winfrey was in a few weeks ago and she had Matson sauce. I love the fact Oprah Winfrey has had fish and chips with Matson sauce. She knows Matson.”

Kerridge has done a lot in his books and on television to demystify cooking. He told the festival it was good to have a microwave in any home kitchen and fine to use stock cubes.

He also gave the audience a potentially life-changing tip: roast your mince.

Most people making a bolognese sauce will chop and fry onions and garlic, add some dried herbs and “throw in a packet of mince, stir it around until it goes a bit grey and all that water comes out of it”.

Instead, he said, put the mince on a roasting tray for an hour in the oven, stirring occasionally. “Texturally, it is amazing. It goes really dry and crunchy and you put it in the stock and tomatoes it rehydrates but it still has this lovely texture. The flavour is massive,” Kerridge told the festival.