Bafta award-winning actress Joanna Scanlan enjoys a challenge.

Best known for her starring roles in The Thick Of It, The Larkins and Notes On A Scandal, the 60-year-old actress' latest project, Welsh psychological thriller Y Golau, proved to be just that.

Directly translated into English as The Light In The Hall, the gripping and decidedly dark six-part drama centres around murdered teenager Ela Roberts. With Scanlan playing Ela's grieving mother Sharon, the drama also stars Killing Eve's Alexandra Roach as former friend and journalist Cat Donato, and Game Of Thrones star Iwan Rheon as convicted murderer Joe Pritchard.

Ahead of the series arriving on S4C and BBC iPlayer, we speak with Scanlan to discover more.

YOUR NEW SERIES Y GOLAU IS THRILLING, WAS IT AN ENJOYABLE PROJECT TO BE A PART OF?

The Light In The Hall has been one of my career highlights. I loved every single moment, even though it's also been one of the hardest things I've had to do. Pleasure and pain mixed up together. Wales is a wonderful place to work. I've worked there a lot anyway, in the English language, but Welsh language TV is quite special.

YOU HAVE A STRONG BACKGROUND IN COMEDY, DOES THIS PROJECT MARK A NEW DIRECTION?

I'm only really going to use excellence as my criteria for work. Of course, the more opportunities for interesting work at all levels the better. Yes, of course I would like to be in the next James Bond film. But I'd also like to be leading interesting community projects. I've never been somebody who just wants to restrict myself to a very narrow palette.

CAN YOU TELL US A BIT ABOUT SHARON, YOUR CHARACTER IN Y GOLAU?

Sharon is an emotionally driven individual. She spent 15 years emotionally raging, grieving, weeping and screaming about the fact the convicted murderer will not say where the body of her daughter is. I think she surprises herself, in the fact that she has no more respectable boundaries. She is so rageful that she has to take things into her own hands.

CAN YOU TELL US MORE ABOUT WORKING ALONGSIDE YOUR CO-STARS?

For me, it was a joy working with Alex Roach, who I've worked with a lot before, who's such a tremendous actress. I think one of Britain's best young actors. She's right at the top for me. So it was a lovely thing to just be there, live there, and work in the Welsh language.

IS IT TRUE THAT YOU HAD TO LEARN BOTH ENGLISH AND WELSH VERSIONS OF THE SCRIPT?

Yes, we were shooting the programme in both English and Welsh. So you're kind of complicating it a little bit further, because you've got an English language version in your head and a Welsh language version. So, I'd learned my line, but what came back at me was a Welsh actor speaking their own language, speaking their emotional truth.

WHAT WERE YOUR FIRST THOUGHTS WHEN IT CAME TO TAKING ON A WELSH SPEAKING ROLE?

When I was asked to do this, I initially thought, 'Oh, my God, this is an incredible honour to be asked to act in Welsh!' - a kind of dream I've had since I was a child. I did lots of drama at school in a Welsh language environment, but I was never a Welsh speaker. However, when we actually got going, I was useless at it. Completely hopeless and pathetic. My niece came down to stay with me and she just drilled me. She's North Walian, and that's where my character's from.

WAS IT YOUR FIRST TIME LEARNING A NEW LANGUAGE FOR A ROLE?

Well, I had done a show before, Iaith ar Daith, which is a factual entertainment show where they have so-called celebrities, such as myself, and they [pair us] with a first language speaker. You go on a journey through Wales and learn Welsh. I did that last year and I loved it. I surprised myself that I could, by the end of it, ask if you'd like a cup of tea! And from there, it was a springboard really to being able to learn a lot more.

DO YOU CONSIDER YOURSELF A WELSH SPEAKER NOW?

I started to eavesdrop on things, so it got a lot better. But there were times when I'd have to sit there with the stinging humiliation of public failure, because I would say things that were so wrong, and so laughably ridiculous. They were very polite. They never did laugh at me.

DID YOU TAKE ANYTHING AWAY FROM THIS PROJECT ON A PERSONAL LEVEL?

It's a very important piece of television because it talks about the way our memories and our prejudices can misguide us - from the truth, looking at ourselves, and from our own responsibilities. A lot of the people in this story are wrong about what they think is the truth. And that, I think, chimes for me in real life. You can [have] some kind of self-righteous idea [of how] you remember events, but actually, when they're examined, they're not correct. And you need to go outside of your own subjective feelings to find the truth.

IT'S ALSO A TIMELY PROJECT, ISN'T IT?

It's a very timely and important piece of drama, because one woman is killed every three days in the United Kingdom [2021 Femicide Census]. In 2021, 21 women were murdered in London. The impact on their families and loved ones is huge. So, I think it's a very important story to talk about - and the consequences of murder, how we look at the truth, and where we find the truth.

Y Golau airs on S4C tomorrow and will also be available to stream on BBC iPlayer