HER face is on billboards all over Manchester promoting Beginning which has opened at Manchester’s Royal Exchange Theatre.

But it’s doubtful if any of the thousands of commuters who see them - or indeed the audiences who will come to the Exchange over the next few weeks - will recognise Erin Shanagher from her early days at the theatre.

They will probably know her from ITV’s detective drama The Bay or even through her role in Peaky Blinders but not through her first contact with the Royal Exchange.

Messenger Newspapers: Erin Shanagher in rehearsal for Beginning (Picture: Chris Payne)

“You know what? I was the chocolate girl,” she laughed. “I would sell posh chocolates and then when the shows would start, it would go dark, I’d turn off the lights on the fridges and I’d sit there in the dark and watch the shows through the glass.

“I’d gone to college and to university thinking that I wanted to to be an actor but I didn’t know anyone who could give me advice, I didn’t go to drama classes and yet I had the privilege of getting this access to the backstage areas and sit in the dark and learn.

“I did a lot of theatre and had toured a one woman show but here I was watching people so skilled, so seasoned it was phenomenal. It was an honour to sell chocolates and watch them.”

It has taken Erin 15 years to move from sales to star and Beginning is her first production at the Royal Exchange. She plays Laura, an apparently successful businesswoman who throws a party at her flat. At the end of the night she finds herself alone with Danny who came as someone’s guest and is ‘last man standing’.

The play - a two-hander by David Eldridge - looks at how the strangers get to know each other and is a beautifully observed study of two people gradually discovering more about one another.

“It’s brilliantly written,” said Erin. “You think one thing’s going to happen and then something will be said and everything changes and then there are constant U-turns. It is such a human play, there are things that happen in every relationship, in every family. On the surface it sounds simple but when you scratch under the surface it’s so complex.

“There’s a lot of snakes and ladders where you think we’re getting somewhere then it’s back to zero and we start again. I think it asks questions of the audience who don’t know what to expect or how they should feel about these two characters and it’s good that they go on this journey with the two of us.”

Danny is played by Gerard Kearns, a regular on the groundbreaking Channel 4 comedy drama Shameless.

“I’m not sure if he remembers or not but Gerard and I did a radio play together years ago,” said Erin. “There was a kissing scene but because it was radio we were both stood in front of a microphone kissing the back of our hands.

“But he’s a dream to work with; he’s a sparring partner and is so generous and fun. He’s someone you can trust.”

Given that they are the only two actors on stage throughout the production, that trust is vital.

“To be so exposed in the round with something so intimate is terrifying and thrilling all at once,” said Erin. “There’s nowhere to hide. But what is also wonderful is that audience goes on the ride with you. They are stuck in that flat as well. There isn’t any separation.”

Writer David Eldridge spent time in rehearsals with the two actors.

“He was so generous and so giving,” said Erin. “We would ask him questions and he was adamant ‘this is yours now. It doesn’t matter what I think. I can help you if you want that but it is your story to tell in Manchester’. That is so rare.”

Beginnings which has had successful runs in the West End and in theatres around the world has been specially re-written by David so that it is set in Manchester and all the references are local.

So what does Erin hope audiences will take from the production?

“It is a play which does have that universal appeal,” she said. “I hope some might make a really great decision because they have seen it; they might take a chance because of it; they might forgive themselves or just realise it is OK to mess up because that’s what we do.”

Beginning, Royal Exchange Theatre, Manchester, until March 11. Details from www.royalexchange.co.uk