Scottish performer Katie Leung's first foray into acting wasn't exactly planned. Her father noticed a casting call for Harry Potter and the Goblet of Fire and suggested she go for an audition. She therefore broke countless teen-girl hearts in her first ever acting role playing Cho Chang, Harry Potter's first love interest in the film adaptations of JK Rowling's books. Since then, she has taken to the stage in Wild Swans, starred at the National Theatre in The World of Extreme Happiness, at the Royal Court in You For Me For You and at Hampstead Theatre in Tony Kishner's recent Iho. Here she explains more about Snow in Midsummer - the first project in the RSC's bid to bring Chinese classics to a modern Western audience - and why she decided to pursue acting as a career after the Harry Potter films.

So Snow in Midsummer is an old Chinese tale?
It's a very modern adaptation of a 13th century play which is basically about a young widow named Dou Yi who who is executed for a murder that she didn't commit. She puts a curse on the town and returns as a ghost to seek justice.

You've just come out of rehearsal wearing knee pads, is it quite physical?
We're still exploring the physicality but we are trying to find clarity between the two worlds and lighting, sound and all that magic will help to achieve it.

Has adapter Frances Ya-Chu Cowhig changed it a lot?
I can't say much because it's a bit of a thriller, but she has brilliantly changed it in terms of the characters.

It is an ancient story, touched by the supernatural, how does it speak to today?
It's the same with Shakespeare: if it's a good story then it should still speak to audiences today. Especially because it is about the injustices of the world. It's not difficult to find inspiration because of what is happening [around us]. I don't think it will be something that the audience will find difficult to grasp.

Was Francis in rehearsals alot?
She was in every day at the very beginning. I am quite used to working with her, because we did The World of Extreme Happiness at the National Theatre, and she gets a lot of inspiration from watching rehearsals. The script was free to change and adapt according to what she was seeing in rehearsal rooms. It wasn't until the second week that we had 95 per cent of the script locked down.

Is working on a brand new piece very exciting?
This is the fourth play I've done and each of them have been new writing. I wouldn't know what it's like to not have a writer in the room.

That will be weird when you take on something like a Tennessee Williams...
Absolutely. Which I look forward to doing someday.

What made you jump for this job?
This was my first time working with the RSC, but I think it always depends on the script. It was obviously knowing Francis, knowing her work and that she's a fabulous writer. It didn't take long for me to decide to be a part of it. And getting to work with Justin [Audibert, the director]. It was a really good vibe.

Snow in Midsummer is part of the RSC's new Chinese translation focus, is it an important scheme?
I think it's a wonderful thing. It's really important to give audiences an insight into different cultures. I'm British, as much as anyone else, there's certain aspects of [Chinese] culture that I learnt about growing up but there's so much that I don't know about it as well. So I'm learning a lot.

Did you have ambitions to be an actress when you were growing up?
No. Perhaps the reason was that I didn't see anybody who looked like me on television, and also because I was very shy and didn't have drama at my school. It wasn't until I auditioned for Harry Potter that I realised acting was a possibility. Even after I had finished on the films I didn't know if I could act. I went back to college to study photography but I realised that would be as precarious as an acting career. So I went back to acting. I was cast in Wild Swans at the Young Vic in my final year of my photography degree.

You had never been on stage before at that point or been to drama school...
It spurred me on because I was surrounded by actors who had trained and it made me realise how much I didn't know about simple things like stagecraft, voice work, warming up before a show. It was inspiring watching fellow actors having a process for what they do before a show. It just re-ignited a passion - or maybe just initiated it because I had never been on stage before. So that's when I decided to go to drama school. I graduated from the Royal Conservatoire in 2015. They were really good to me because they allowed me to work while I was studying there.

Was it a difficult decision to go to drama school? Lots of people tend to skip it if they have the work...
It was. But I had met a tutor on a summer school course and he saw potential in me and told me to apply. Part of [being hesitant] was that I was afraid I would be recognised and judged from being watched in those films, so that held me back for a bit. But I auditioned and got in and I am really glad that I did.

Were you surprised when JK Rowling announced the next Harry Potter story would be a play?
The first thing that popped into my head was whether JK Rowling would be involved. Because if she wasn't then it probably wasn't going to be any good. But she played a big part in recreating it, so there's no question that it would be epic.

Have you seen the show?
I have watched it recently and it was fucking brilliant! I was really impressed with the performances. It brought back many memories but I was blown away by how much I could empathise with every character onstage. It made everyone very human. I loved every minute of it.

Snow in Midsummer runs at the Swan Theatre until 25 March.