Agyeman has been answering my questions politely for almost an hour before she leans forward, smiles and asks, 'So what's this for again?' I tell her that she's one of our Faces of 2007. 'Really? Oh that's so nice!'

This exchange tells you two important things about the 28-year-old Agyeman. The first is that she's genuinely surprised that anyone could be interested in her. The second is that she's so impeccably well-mannered, she'll happily chat away to a journalist for a considerable amount of time without knowing why, lest she might offend me by asking what exactly she's doing there.

She's clearly never been one to blow her own trumpet, or even manage a feeble self-congratulatory whistle on a school recorder. But she does acknowledge that 2007 has been 'an incredible year. It feels like it's been on fast-forward'.

In March Agyeman entered cult television folklore by debuting as the new assistant to the 10th Dr Who, David Tennant. There was a fever pitch of anticipation surrounding her appearance for several reasons, predominantly because she was replacing Billie Piper, who had proved extraordinarily successful in the role of Rose Tyler. But Agyeman was also the first black assistant in the programme's four-decade history.

'It's an honour,' she says, 'but the flip-side of that is that you get labelled in a way that non-black actors never do. If we're still making comments about "the first black this..." in 50 years, then there is a problem.'

In person, Agyeman is strikingly beautiful - an almond-eyed hybrid of her Iranian mother, Azar, and Ghanaian father, Osei. She grew up on Woodberry Down council estate in Hackney, north London, before studying drama at Middlesex University.

'There's this preconception that the estate was overrun by guns and drugs. Well, that wasn't my experience. There wasn't a gun in my life. I had a wonderful time. My days would be spent playing with neighbours and then being called in for tea.'

So how is a down-to-earth girl from Hackney coping with the surreal sci-fi Tardis time shifts and the motley assortment of obsessive Doctor Who fans?

'I've just about got to the point where I can see myself as part of it without getting palpitations,' she laughs. 'I do get a couple of people stopping me in the street after every episode but it's normally when I've gone out totally unprepared, without make-up.

'It feels like I've been validated as an actress...'

She breaks off, chewing anxiously on her bottom lip. 'If that doesn't sound too egotistical.'

Source: The Observer December 2007