Charlotte Riley and I are discussing pogonophobia when the pubic hair comparison comes up.

"My friend sent me this thing on What's App the other day about female fashions in pubic hair trimming versus men's trimming of their faces from the 1970s," Riley tells me. "So as women's bushes have got smaller and smaller men's facial hair has got larger and larger. That really tickled me."

Well it would I almost say as she is tries to find it on her phone. She then looks up at me. "I'm going to regret saying this," before bursting out laughing.

While I try to imagine what the hipster beard/female waxing graph might possibly look like (and whether it might radically change our idea of the Hoxton Fin) Riley has returned to my original question. "I'm not scared of beards," she confirms once I've explained what pogonophobia is. "That's a great word. I'm going to write that down.

"I think beards are fab as long as there is no food in them and they smell nice. Yeah, they're better than short and spiky because that's not good for women's delicate skin."

I ask of course because Riley's better half - Tom Hardy if you didn't know - often spouts some radical facial hair in his roles (when he's not wearing a mask on his face in Batman movies). There was the handlebar tache in Bronson, the full set in Peaky Blinders and, out this week, the stubbly look in the new Mad Max film. "I just love him however he comes," Riley says sweetly.

Riley's own thespian transformations tend to be less showy (or hairy for that matter) but just as effective. She's a face you might recognise from Peaky Blinders, medieval TV drama World's End, lurking in the background behind Tom Cruise and Emily Blunt in the rather silly sci-fi thriller Edge of Tomorrow or making a splash in the 2009 TV version of Wuthering Heights in which she starred opposite said Mr Hardy (in case you were wondering how they met).

But this might be her moment. She is one of the lead roles in the BBC's much-trailed, already much-lauded new fantasy drama Jonathan Strange and Mr Norrell, in which she plays Arabella, married to the titular Jonathan Strange (Bertie Carvel to you and me; Eddie Marson plays Mr Norrell). And that's just for starters. There's also a big-screen thriller opposite our very own Gerard Butler (London Has Fallen) and Ron Howard's latest film In the Heart of the Sea.

In short, she's keeping busy.

In fact Riley has travelled down to London from Liverpool today just to meet me. Okay, maybe to spend a bit of time at home too. She's up in Liverpool filming Stephen Poliakoff's latest drama Close to the Enemy, set in the post-war years. "I'm particularly passionate about the forties, so I'm loving learning to swing dance at the moment," she says gleefully. But only after she says how much she wanted to work with the writer and director who gave us Glorious 39 and Caught on a Train.

Close to the Edge is another costume drama. We are obsessed with them, aren't we, Charlotte? "I think it's because the weather's so cold and the past seems so cosy and warm."

In person Riley is a bright-eyed, brown-eyed girl with a northern English accent (she grew up near Middlesbrough) and a huge sense of fun. I have brought a bundle of folded-up bits of paper with me which I dump onto the table when we sit down. "We'll get to these later," I say. "You can't tease me like that," She complains.

Okay. Each contains a word, I explain, and you have to tell me the first thing that comes into your head when you read the word.

But before we go there maybe we should talk about Jonathan Strange first. A seven-part adaptation of Susannah Clarke's fantasy novel (think the Battle of Waterloo but with magic), it combines costume drama with CGI. "I didn't get to see what they did with the magic until I watched the previews, Riley says. "They really did keep the green scene stuff to an absolute minimum. And then you get to watch the CGI trickery afterwards and go 'oh wow. Amazing.' Sand horses appear and statues move and all that good stuff."

It's dark too, she says. "I loved the marriage of that with the really human stories, in particular Arabella and Jonathan's story.

"She keeps Jonathan - who is this mad eccentric - grounded. The banter between the two of them is quite modern in some ways. That keeps things light and fun. She was great fun to play."

In what ways is she most like Arabella? "She's pretty nosy. I'm quite a nosy person. My dad says I have the ears of an elephant. I can hear everything that's going on. I hate missing out on things.

"Nosy-slash-inquisitive. I'm intrigued by people. There's a saying up north. 'Shy bairns get nowt.' You don't ask, you don't get. You don't enquire, you don't learn."

So, let's learn what we can about Ms Riley. Charlotte, pick a word.

Charlotte Riley on love

"I have recently discovered my love of dogs. I was really badly attacked by a dog when I was a kid. I was never scared of dogs. I just never had a great love for them. Now we have two dogs and it's really expanded my love for the whole animal kingdom. I always thought people who come home early from a night out to get back to their dogs or bought their dogs stockings for Christmas were just the saddest human beings ever. But now I am one of those sad human beings."

When did you first fall in love Charlotte?

"Probably when I saw New Kids on the Block on Top of the Pops. I fell in love with Joey. I've still got their albums somewhere."

Charlotte Riley on culture

It makes me think of yoghurt."

Charlotte Riley grew up in Stockton on Tees, the youngest daughter of an engineer and a nurse. "My brother and sister are 10 and 11 years older than me," she says. "They'll have it that I wasn't, but I was the little accident that came along. It was like having two sets of parents actually. My brother and sister were really involved in bringing me up. I had the concentrated love of four people."

At the end of junior school she played Captain Hook in the school play and distinctly remembers loving the experience. That was the beginning of something, though it took her a while to get there.

She'd spend her teenage days "dancing in terrible nightclubs where the floors lit up and everything was sticky" before going to Durham University where she studied linguistics. Acting was a goal. She just wasn't sure how to get there.

It was always an instinctive thing for her. It's the physicality of acting she likes (she's done courses at clown school in her time). "I wasn't brought up going to the theatre and reading Shakespeare. I didn't know who the Three Sisters were when I auditioned for my first Chekov play."

She comes from a working-class background but she's not sure she qualifies as that any more. "I think my parents would definitely have described themselves as working class. For me it's not something that sits in my consciousness or something I define myself by.

"They both grew up with very little in prefabs in Middlesbrough. My dad was a fitter in ICI and the one thing I really appreciate is they worked so hard all their lives so I could have much more of a choice in what I wanted to do with my life.

"I remember being challenged once as to why I was taking time out after university which is actually when I wrote some plays and worked out what I was going to do. I was challenged by a friend's parents and I said 'well, my parents worked their arses off all their life so I could have that choice.'

In her career she's only used her own accent twice. "I play people who are very powerful and have a huge amount of money. It's quite diverse. The point of being an actor is that hopefully you can transform and play people from different walks of life."

It's a licence to move between the classes? "Yeah, exactly."

Inevitably she did the Edinburgh thing, squeezed in four to a room in sleeping bags with the Durham Revue in a tiny flat above the World's End pub. Appearing at the fringe, she says, is "possibly one of the most terrifying stages you'll ever perform on because the audience might be walking past you on the Royal Mile the next day."

Her experiences there inspired her to apply to the London Academy of Music and Dramatic Art in London. A year after graduating she was playing Cathy to Hardy's Heathcliff.

About your better half, I say. You know I'm contractually obliged to ask a question about him. "Hah," she laughs. So, let's see. Is he good around the house?

"He's great around the house. We do designated things. I love recycling. He's good at making the bed. It works brilliantly."

Making the bed does not seem the most arduous task but let it lie. Some other quick questions, Charlotte. What's the hardest thing to do in acting? Playing dead, sex scenes or walking a straight line? "Sex scenes. My first question is 'are they necessary?' It's generally that that makes me go 'oh really?'"

Right. Gerard Butler. What's the most Scottish thing about him? "Just his sense of humour ..." She looks across the table. I don't suppose that's particularly Scottish."

Of course it is, Charlotte. "Yeah, you're all fucking hilarious."

Are you driven? "I wouldn't say I am in the way I see it in other people. People often say to you 'what's your five-year plan?' I don't really work like that. As things come along then I get excited about them."

But, Riley says, she doesn't just bob along. "I'm not directionless. I want to make positive choices so that I'm doing stuff that I enjoy as much of the time as I can." And if nothing is in the offing - less so now you'd imagine as her reputation grows - she can always do some writing or painting.

Come on, though, Charlotte, you'd be miserable if there was no work on the horizon. Do actors sit about all day bitching like journalists? "They do. The collective term is a 'moan of actors'. But I think it depends on who you hang out with. It does my head in, people whinging too much."

We've time for another word. She opens the folded paper. "Failure," she reads. "I feel quite passionate about theatre. I know that sounds really weird. I think getting things wrong is just as important as getting things right. Because you learn. How many amazing inventions have been created by getting things wrong? It's all a matter of perspective, isn't it? Failure. It can be painful but equally you learn so much.

"I don't see failure as failure. I just see it as an opportunity to get it right ... " She plays back in her head what she's just said. "... Which sounds like one of those really vomit-worth positive affirmation things. But I feel quite passionate about it."

When was the last time she feels she failed? "I think you feel it on a daily basis. When you feel you could have been a bit more tolerant or compassionate. Equally, you can watch yourself in something in terms of your acting and just be 'rubbish. I won't be doing it like that again.'

She is animated now. Keen to dig away at the idea.

"I went back to my old school and the teachers thought it was really strange that I did a speech about failure. Education is so much about ticking boxes and getting answers right. Children are being brought up to think that it's black or white, right or wrong. There needs to be more room to go 'you're at school. You can epically get it wrong and enjoy getting it wrong and then find a different way of doing it. I just think it's really sad when you see people feeling really stifled by a society that's about villainising people for fucking up and getting it wrong."

Charlotte Riley has not been getting it wrong. Charlotte Riley loves dogs and doesn't mind beards. Charlotte Riley doesn't make the bed. Consider this an introduction.

Jonathan Strange and Mr Norrell starts on BBC One tomorrow night at 9pm.