Ashley Jensen on new family film All Stars

“I was standing in a street in Coventry, filming in the snow, going, ‘Did that last six years of my life really happen?’ ” The Dumfries and Galloway-born actress is referring to her extended stint in Hollywood. Having parlayed her role as the endearingly guileless Maggie Jacobs in Extras into a successful American TV career with hit show Ugly Betty and short-lived sitcom Accidentally on Purpose, she certainly had great fun embracing the glamorous lifestyle that came with it.

Now, though, she’s back living and working in the UK, having returned last year with her actor husband Terrence Beesley and their young son Frankie. It’s perhaps not surprising that her time in Los Angeles feels “a bit surreal”.

Not that there was ever much chance of Jensen turning into a diva. “I think because I did become a well-known face in my thirties and not in my twenties, I was pretty settled in my boots and I knew who I was,” she says. “And I think there’s a sort of Scottish thing too where you don’t take yourself too seriously and you don’t get carried away with your own sense of self-importance.”

To this end, she’s in Glasgow to talk about All Stars, a new family film in which she willingly cedes the limelight to its mostly teen cast. The film, an offshoot from the British-made Street Dance movies, follows the efforts of a group of younger teens – led by Theo Stevenson and former Got to Dance talent show winner Akai Osei – as they set about trying to save their local youth centre from demolition by putting on a street dance-themed talent show.

Jensen plays the youth centre’s sympathetic manager, and while she makes no secret of the fact that she’s there as a foil for the kids, her character, Gina, does underscore how important it is for children to “have a place where they can be themselves and be creative and sort of learn who they are”.

It’s something Jensen could relate to easily enough. Having attended the National Youth Theatre when she was a teenager, she understands how helpful these kinds of organisations, community centres and extra-curricular activities can be for young people.

“It’s so important for self-expression and for growing-up,” she nods. “I mean, I don’t even think places like the National Youth Theatre (NYT) are necessarily about wanting to be an actor when you grow up. They’re about meeting people from different backgrounds and different religions and different cultures, and mixing with people that you wouldn’t ordinarily meet.”

That said, Jensen does admit that she was pretty sold on her future career the moment she left her hometown of Annan, aged 14, to attend the NYT. “I think now of how brave my mother was to let me go down and live in London for a month. I think she thought, ‘I don’t know where this acting malarkey has come from, but I’ll let her do that and she’ll come back and see sense and get on with thinking about a proper job.’ And of course, I came back and went, ‘No, this is absolutely what I want to do when I grow up’.”

At the time, alumni included Helen Mirren, Ben Kingsley and Daniel Day-Lewis, though Jensen’s year turned out pretty well too: her classmates included Tom Hollander and some guy called Daniel Craig. What was the future James Bond like back then? “Well,” she muses, “he was always good looking. I was just sort of aware of him in the distance. To be honest, he was always pretty cool.” She thinks about it some more and smiles. “He would never have noticed me, put it that way: a wee, small, lumpy lassie from a farming town in Scotland!”

That kind of self-deprecation is one of the reasons people respond to Jensen, so I’m curious if, after working on All Stars with kids who have grown up in the era of The X Factor, she thinks teenagers approaching her profession are savvier than they were when she was that age.

“I think that children that are acting are always pretty savvy anyway because you’re conducting yourself around adults a lot of the time, aren’t you? But there is this worry now that children just want to be famous.

“Not the guys I’ve been working with,” she adds. Fourteen-year-old Akai Osei, she says, “really, really knows about hard work,” and 15-year-old Theo Stevenson – who has already notched up critically acclaimed performances at the Young Vic and the National Theatre – has been working, as Jensen points out, since he was tiny.

“But there are a lot of people who don’t realise there is quite a lot of hard work on the way to getting there. I always thought it was funny that when I got Extras I was ‘Overnight Sensation Ashley Jensen!’ who’d been working for 15 years in theatre and television and grafting away doing touring theatre.”

It was a little ironic – she hadn’t exactly been relegated to the background in those pre-Extras days. On stage at Manchester’s Royal Exchange, for instance, she played Regan opposite Tom Courtenay and David Tennant in King Lear. And she got her first break on television back in 1993, playing Billy Connolly’s daughter in the Glaswegian crime drama Down Among the Big Boys.

She laughs as she remembers her first day of filming the latter – dressed as a bride in a big meringue dress, and babbling away to Connolly in between takes about earning her milkmaid’s badge when she was in the Guides. “He thought this was hilarious and I remember going home and calling my mum and going, ‘I made Billy Connolly laugh!’ I couldn’t believe it.”

That she could be funny essentially being herself wasn’t something she gave much thought to until she went to America to do Ugly Betty and Accidentally on Purpose. After auditioning in an American accent, she realised it was easier to be funny if she just made the characters from Annan. “When you’ve lived with your own accent, you know your rhythms, so it’s much more instinctive.”

Since moving back to the UK, she’s been keen to mix things up a bit more on the acting front. In addition to making All Stars, she returned to the theatre late last year in a West End production of Alan Ayckbourn’s A Chorus of Disapproval. On the drama front, there are plans to return to Scotland to shoot a film with Kevin McKidd in the Highlands called Indian Summer – although as far as she knows, the project hasn’t yet been green-lit. She’s also recently wrapped production on a new television legal thriller called The Escape Artist in which she plays the spouse of her old pal David Tennant. Having first worked him more than 20 years ago on a Brecht play, and then again in King Lear, it has been another surreal experience.

“We were laughing about this the other week,” says Jensen. “We worked together in 1990 as part of 7:84 when we were in The Resistible Rise of Arturo Ui together, and we were like, ‘Oh my God, look at us now! We’re playing husband and wife. That’s hilarious.”

• All Stars is in cinemas nationwide from tomorrow. The Escape Artist will screen on the BBC later this year.