Ben Winston strolls into his offices on the CBS Studio lot in West Hollywood, the headquarters for some of the biggest TV shows on the planet, from Star Trek to The Big Bang Theory. You’d never guess that he was a relative newcomer to the City of Angels.

Clad in the de facto LA uniform of black t-shirt, jeans, and a tan, he makes a quick detour to say hello to pop star Joe Jonas, who is in the building to film a stand-alone episode of Carpool Karaoke, of which Winston is a producer. During our interview, he apologetically breaks off to text Bruno Mars, with whom he’s working on another project. So far, so LA.

But Winston’s journey from north London to Hollywood wasn’t initially plain sailing. He moved here with his wife more than two years ago to helm The Late Late Show, hosted by friend and business partner James Corden. At the time Winston was 34, the youngest ever show-runner in American late-night television while Gavin and Stacey star Corden was all but unknown in the US. There was scepticism about this British duo taking over one of the most prestigious slots in American television. “It was incredibly hard to book [guests] when we first started,” Winston admits.

Tom Hanks turned their fortunes around, by agreeing not only to be the show’s first guest but also do a self-deprecating skit with Corden.

“I had a phone call with him to pitch the idea about doing a [comedic] retrospective of his career and that was probably my first ever ‘pinch-me’ Hollywood moment, where I’m on the phone to Tom Hanks and he wants to know where in London I’m from — Hampstead Garden Suburb — and he’s asking me all sorts of questions. It was a huge turning-point in the show.” Hanks features on the latest series of Carpool Karaoke too.

If there are any doubters left, they got their answer at the Creative Arts Emmy awards last weekend. Winston, along with Cordon and colleague Rob Crabbe, picked up two: Best Variety Special for Carpool Karaoke Primetime Special and Special Class Programme for The Tonys.

When I ask which of The Late Late Show’s numerous illustrious guests — from Adele to Samuel L Jackson — have given the biggest thrill, Winston, son of Professor Robert Winston, the daddy of IVF, doesn’t hesitate. “My dad came on the show once,” he beams from underneath a sketch of Winston Sr.

“Him and James did some experiments and blew up some stuff on the stage. It was really fun.” Viewers agree: the clip has garnered over a million views on YouTube and attracted hundreds of comments comparing Professor Winston to Johnny Depp and demanding he be given his own US show.

If anyone could make that happen, it’s undoubtedly his son. While many in the industry are wary of mixing business and pleasure, Winston’s career is characterised by his family-orientated outlook, with little distinction between the personal and the professional. He still works with his childhood friends — Leo Pearlman, Ben Turner and Gabe Turner — at Fulwell 73, the production company the quartet set up together after university, and is now managing the US arm from LA.

“Gabe and I were in the same pram because our mums are best friends,” he explains. “Gabe and Ben are brothers. Leo is their cousin.”

Equally, many of the public figures he’s encountered through his work have since become friends, from Harry Styles, his former lodger, whom he first met while working on The X Factor, to Corden, whom he has known since he was 18. Winston was best man at Corden’s wedding in 2012 and recently the Hillingdon-born comedian was made a fifth partner in Fulwell.

“James has been quasi-partner for years,” Winston explains. “He has always been so involved in everything we have done and we have made so many shows with him.”

Was there a formal induction? “Not really. I think we went out for dinner. There was no big, formal — he didn’t have a barmitzvah.”

For someone who is so close to his family — his house in London is just 10 minutes from his parents and his in-laws — the move to LA has been, in some ways, bittersweet, especially since the birth of his first child, Ruby, nine months ago.

“I don’t think I’m moving here forever. I’d like my daughter to grow up in the UK but I think right now for what we’re doing and the opportunities we have, we’d be mad to be anywhere else.” It’s also meant he’s been somewhat removed from the political turmoil that has rocked the UK over the past few months, although Corden and Winston uprooted the show from Los Angeles to London in June for three episodes in the same week as both the London Bridge terror attacks and the snap General Election.

“We planned it six months in advance,” he recalls. “It turned out be a very bizarre week.”

Not least because the entire Late Late Show team were staying at a hotel in London Bridge during the attack, which caused, he says, “pandemonium”, although fortunately none was injured. “It felt very powerful to be on air in 155 countries saying ‘this is London’,” he says of their UK shows.

“This is the London we know and are proud of. It’s not a London that is afraid and I think that was a really great message for America and the rest of the world to see.”

As for the General Election, Winston, a life-long Labour voter (his father sits on the Labour bench in the House of Lords), admits that he changed his vote for the first time this year. “I’m a member of the Labour party but I don’t necessarily feel affiliated to Jeremy Corbyn’s Labour at all,” he reveals. “I did vote. I didn’t vote for Labour or the Tories because I felt like neither resonated for me but I have voted Labour all my life until now.”

“I think there’s political turmoil on both sides of the Atlantic,” he says. “It’s very depressing right now. Doing the job that we do you can’t avoid it because people are looking to our shows, bizarrely, for the news, in a way. If they don’t want to watch the real news, they watch the jokes about the news.”

While Donald Trump has undoubtedly been a boost to ratings, does Winston worry that television is a dying medium?

“I don’t think television is dying,” he says. “The fact is, Netflix is still television, so what’s interesting is there is more money and power being put into television than ever before and actually it’s just being viewed in a different way.”

“The thing that is not dying, but becoming less important, is a schedule, as people can watch shows now whenever they want,” he explains. ”But when a tragedy happens, when a terrorist attack happens, everybody is together and they are gathered around that television. When a sporting event happens, whether it be the FA Cup Final or the Superbowl, everybody is gathered together and they’re watching that right now. Those moments really show the power of television and it’s not a medium that’s going to fade because the only place you want to be is in front of your box.”

Having said that, one of Fulwell’s strengths is diversity of output. The company has produced everything from documentaries to music videos. At the moment, Winston says proudly, Gabe and Ben are working on a documentary about Motown while Leo is in talks with Universal Pictures about a film.

And yet, in an illustration of the values that underpin the company, they continue to produce Jewish charity videos, including for Magen David Adom and Chai Cancer Care, alongside series such as Carpool Karaoke, a segment from The Late Late Show that has been spun off into a stand-alone series for Apple Music featuring celebrities from Will Smith to Gwyneth Paltrow.

While Winston might look the part of the LA native, he admits there are times when he still can’t quite believe where he’s ended up. “There have definitely been some moments that have been jaw-dropping for us,” he says, singling out an episode of Carpool Karaoke with the then First Lady, Michelle Obama, as the most improbable. “That was a real moment where you’re like, ‘I’m not quite sure how this all happened’,” he recalls.

“Suddenly we’re in the West Wing, we’re looking in the Oval office and we’re going outside. I was in the car behind [James and Obama] with her Secret Service personal security guard just driving in a circle around the White House again and again for like an hour watching her rap to Missy Elliott.” From North West London to the White House: not bad for a boy from the ’burb.

Carpool Karaoke: The Series is out now on applemusic.com/carpoolkaraoke