Shrewsbury chef James on Nigella TV show The Taste

James Sherwin, from Heath Farm, Shrewsbury, is one of just 25 wannabe chefs chosen to compete on The Taste, where Nigella is one of three judges who will comment on just one mouthful of food made by hopefuls.

Mr Sherwin will feature on the opening episode of the Channel 4 show, which will be aired on Tuesday.

It will be the first time Nigella will appear in a British show since she admitted taking cocaine in the past when she appeared as a witness in court last month as two of her former personal assistants were cleared of fraud.

Earlier this week she was interviewed on Good Morning America, when she admitted that the whole experience of the trial had been "mortifying".

Mr Sherwin, who worked as a specialist diabetes nurse for 12 years, now organises pop-up restaurants around Shrewsbury.

He is not a classically trained chef and is totally self-taught.

The show was pre-recorded in October, and Mr Sherwin said he had been told by Channel 4 bosses not to discuss issues relating to Nigella's court appearance.

But he said Lawson and her fellow judges – chef Ludo Lefebvre and food maverick Anthony Bourdain – were "very polite" during the competition.

Mr Sherwin will be seen battling for one of 12 places in the competition on Tuesday's episode.

The 35-year-old father of two will be seen preparing chestnut and crab ravioli with chestnut sprinkles in a crab and fennel bisque – a dish which he spent hours perfecting at his Shropshire home.

"I must have done it about 30 times," said Mr Sherwin.

"I changed the flour, the ratios of meat and the amounts of dark crab meat or light. It was a bit of a nightmare.

"But I think it turned out OK."

Mr Sherwin, who has also spent three years as a mixed martial arts fighter, is staying tight-lipped about his progress on the show.

But he said the filming process, which took place at Pinewood Studios in London, was a fascinating experience.

"I only applied for the show one day as I was a bit bored and saw a questionnaire on Twitter," said Mr Sherwin.

"Then I had a call from the production crew and then I had to produce some food and take it along to them."

He added: "I was amazed to get on to the show as there were some amazing cooks there."

Producing food which would entice the judges in just one mouthful was a challenge for Mr Sherwin – but one which he nevertheless rose to.

"The judges were very polite about the food but perhaps they were like that with everyone," said Mr Sherwin, who has two daughters Poppy, six, and Ava, two.

"I knew I had to produce something that would impress them but that wasn't too clever. It had to not only look good but taste good too as everyone came up with something amazing."

Mr Sherwin's style of cooking on the show differs from that of his pop-up enterprises.

"There I use smoking and foams a lot more." he said. "I deconstruct dishes and then put them together in a different way. But I didn't want to do that sort of thing on the show."

There was no mention of Nigella's legal woes when she appeared on the American version of the show on Thursday – but she did clash with French co-star Lefebvre.

She looked appalled when Los Angeles-based cook Lefebvre condescendingly described her as a "beautiful woman" as she tried to persuade a contestant to join her team.

Speaking on Good Morning America earlier that day, Lawson said that having "distortions" of her private life "put on display" in court was "mortifying".

She said: "It's one of the niceties of the English legal system that you're not allowed any counsel if you're a witness."

Lawson said that her "only desire really was to protect my children as much as possible, which I wasn't, alas, I couldn't always do".

But she said she had "had a very good Christmas" since and was keen to put the experience behind her.

"There are people going through an awful lot worse and to dwell on any of it would be self-pity," she said.