Around this time last year, Seth Rogen almost started World War Three. For a man whose métier is the broadest of broad comedy – in the past 10 years he’s directed, written and starred in a succession of unfeasibly successful films featuring young men in frantic pursuit of sex, weed and freedom – this was an unexpected turn of events.

According to the North Korean government, Rogen was guilty of a “most blatant act of terrorism and war” with The Interview, a crazed farce in which his beleaguered television producer accompanies James Franco’s preening entertainment journalist to Pyongyang to interview Kim Jong‑un. The climax of the film, which was devised by Rogen and his regular collaborator Evan Goldberg, shows the country’s supreme leader being roasted alive by a missile.

North Korean officials were not amused. The fallout was spectacular. The country complained to the UN. There were intimations that if the film were released it might provoke acts of terror (it eventually had a brief showing in cinemas from Christmas Day 2014, with no repercussions). Meanwhile, the “Guardians of Peace”, hackers supposedly acting on behalf of the North Korean government, leaked thousands of embarrassing internal emails and memos from Sony Pictures, the parent company of the film’s financiers. (Among them was an exchange between Rogen and the studio about toning down Kim Jong-un’s death scene: “There are currently four burn marks on his face,” he wrote. “We will take out three of them, leaving only one. We reduce the flaming hair by 50 per cent.”)

It’s hard to believe that the 33-year-old sitting opposite me on a sofa in a Soho penthouse – a man so amiable, so Fozzie Bear-ish, so Canadian – could have been responsible for all this.

Seth Rogen with James Franco in The Interview Credit: AP/Ed Araquel

Did he ever think that provoking a global diplomatic incident might derail his career? “I was already filming another Sony movie by the time the s--- hit the fan,” he says, “and we were going to make Neighbors 2 [a sequel to his 2014 comedy, which co-stars former teen idol Zac Efron, and made £175 million worldwide]. So I knew nothing that bad could happen. And I was cast in the Steve Jobs movie in January, and work kind of heals all wounds. Literally, I was too busy working to think maybe this will have a negative effect on my career.” And out comes a huge, juddering, gurgling laugh.

There’s no arguing with Rogen’s work rate, even less with his success rate. The comedies he’s written in the past eight years, beginning with Superbad in 2007, have made close to £500 million at the global box office. Those he’s starred in – The 40-Year-Old Virgin, Knocked Up, Neighbors, even Michel Gondry’s unloved comic-book adaptation The Green Hornet – have raked in even more.

Along with Rogen came a motley crew of fellow actors including Jonah Hill, Jason Segel, James Franco and Jay Baruchel. They’re an abnormally normal-looking group of men by Hollywood standards (with the exception of the handsome Franco) and it’s their realness, the way they riff off each other and the fact that many have been friends since their late teens, that makes them so appealing. They live a life many teenagers might dream of, making millions cracking jokes with their friends in a haze of marijuana smoke.

Rogen is the group’s alternative leading man, a shlub who’s sharper and angrier than he looks. It’s a persona he started to hone from his first big break in 1999, the short-lived television series Freaks and Geeks. It was there that he met Franco and Segel, as well as Judd Apatow, the most influential comedy producer of his generation and the man who became his Hollywood mentor.

Seth Roge, Jason Segal, James Franco, Linda Cardellini and Busy Philips in television series Freaks and Geeks Credit: Photoshot

Rogen is self-aware enough to realise how effortless his existence might appear. There’s a moment in This Is the End, his (co-)directorial debut, when a passer-by shouts out: “Hey, Seth Rogen, when are you going to do some real acting?”

Perhaps the answer is now, with Steve Jobs, which Rogen describes sweetly as a “fancy movie”. It’s an accurate enough label for a prestige bit of film-making, directed by Danny Boyle, with a script by Aaron Sorkin (The West Wing, The Social Network) and starring high-calibre European thespians in the leading roles: Michael Fassbender as the meticulous Apple co-founder and Kate Winslet as his redoubtable marketing whizz Joanna Hoffman.

Rogen had heard about the script before he read it. “At first I was sceptical that it was something that anyone would be interested in,” he says, laughing, “and then I read the script and was, like, blown away. As a writer it just made me so angry and jealous. It’s a lame analogy, but it was kind of like an Apple product, simple but beautiful.”

The producers wanted Rogen for the part of Steve “Woz” Wozniak, co-founder of Apple and the bearded, recognisably human counterpart to Jobs. “I thought I could do the part, maybe, but I was very self-conscious about trying to inject myself into a movie that I didn’t belong in,” he says, breaking into a laugh.

He auditioned for the part in front of Boyle and Sorkin, and then he heard nothing. For six months there was silence, although Rogen followed the movie’s development closely, as Christian Bale dropped out of the lead role and Sony passed the picture to Universal, and he told all his friends how much he loved the script. And then in November he got the call, just as the chaos around The Interview was at its height.

Woz is Rogen’s first straight role, and he wasn’t quite sure what to expect from the experience. He went to talk to Michael Fassbender on the first day of rehearsals. “I asked him, straight up, 'Are you, like, weird? Do I have to call you Steve? Are you going to be mean to me? I just want to know what the playing field is here.’ ” He laughs. “He was like, 'No!’ He wasn’t in character all the time. Nor Kate either. It wasn’t that different from the process I’m used to. Although we never get to rehearse for a movie normally. And with this we rehearsed for weeks and weeks and weeks.”

The hardest thing was getting used to the machine-gun rhythms of the Aaron Sorkin dialogue. “Remembering the words isn’t hard,” he says, “but it’s the rhythm with the other actors that took the most time. Because it literally says when you have to interrupt the other person, like in a play. When you overlap each other is written, certain words are supposed to overlap other words, and that’s not easy.”

Michael Fassbender as Steve Jobs and Seth Rogen as Steve Wozniak in new biopic Steve Jobs Credit: Universal Pictures/Francois Duhamel

Rogen’s own approach to film-making is looser, to say the least. But like many comedians, he’s fascinated by the craft of writing. He started when he was 12 years old, was performing stand-up by 13, and at the same time began the screenplay that would become Superbad with Evan Goldberg, a boy he’d met at his bar mitzvah class who remains his closest friend.

“At first we were trying to write about funny guys in high school, and then we were like, 'Why don’t we try to write about us?’ None of these people who write high school movies are in high school. That’s what we realised was our advantage, as opposed to our disadvantage, because we were so young and nothing to do with Hollywood and were two Jewish guys in Canada.”

Rogen had a happy childhood in Vancouver, but realised early on that the world was a “f----- up place.” “My dad is, although very nice, nihilistic to some degree. I remember at a very young age asking him, 'Do you think the world’s going to end one day?’ And he was like, 'Oh, Seth, the world ended a very long time ago.’ ” He gives a big, wheezing laugh. “I think that type of attitude had an effect.”

Since his marriage in 2011 to Lauren Miller, an actress and screenwriter he met when he was writing for Da Ali G Show, Rogen’s comedy shows signs of softening. He’s said that Miller has encouraged him to write better female characters, Rogen and Co having previously been accused of painting women as shrewish party-poopers to their lovably useless heroes.

As he’s got older, Rogen has taken on causes – he gave a moving, angry speech at a Senate hearing on Alzheimer’s, which has afflicted his mother-in-law – and been drawn into political controversies (aside from the North Korean moment, last year he was also accused by Washington Post critic Ann Hornaday of promoting a culture of male entitlement that led young men to shoot women they felt had unfairly rejected them).

If life has become more serious, Rogen hasn’t. Having proven himself on Steve Jobs, he’s not pursuing a life in “fancy movies”. No, coming soon is Sausage Party, an animated comedy he co-wrote, in which he, Jonah Hill and James Franco give voice to sausages and Salma Hayek plays a character named Theresa Taco.

“People used to ask, 'Are you working towards something?’ ” he says. “And it was like, 'No. We only make things that we really love and that we’d be devastated if we didn’t get to make.’ Some people look at our films, I’m sure, and think, 'That’s the s--- you love?’ But it is. Every movie we make is our dream movie.”