I worked my way up and got the job of director’s assistant on a film called The Informant, directed by Jim McBride. Ros and John Hubbard were casting the film and, unusually, Jim allowed me to come into casting sessions with him.

I thought it was fascinating. I loved the process and I knew then that this was what I wanted to do.

I went on to work with casting director Maureen Hughes. She’s an incredibly creative person and has an amazing eye for acting talent. She always said, ‘Cast the best actor’, and I’ve always kept that in my head. Because sometimes in the process you’re thinking, ‘Should we go for this person or that person?’ and you find yourself going through all their merits and demerits.

Nowadays, when I get sent a script, I try to read it first without thinking of anybody. People will come to mind and I’ll jot them down, but I’m really trying to get a handle on the world of the story. Then I read it a second time and I’ll start to think of ideas. But I don’t fixate on anybody until I’ve spoken to the director.

Casting is an organic process. You start with your leads and whoever ends up in those parts will have an impact on how you cast the rest of the production. I think of it as a jigsaw puzzle where you start with the middle and you build your cast around that. I’m very careful about all the parts and how they relate back to the leads and how they relate to the world of the film. I think it really adds to the texture of the film — and I don’t like looking at an unfinished jigsaw.

When actors have a strong sense of themselves, it really translates [in an audition]. I cast Paul Mescal for an RTÉ comedy series called Bump and he was unusually fully formed for a young actor. Anyone who saw his final-year production in college would say the same thing.

I cast Saoirse Ronan in The Clinic when she was 10, and even at a young age she just had a very clear sense of herself. She was very understated. Her dad was an actor so she knew how to act for camera, which was very unusual. When I look at her now she’s the exact same. It’s the exact same energy.

I think when you have that self-assurance you don’t need to apply any bravura. You have the assurance that you don’t need to be perfect and you can make mistakes and experiment.

If an actor is struggling with an accent, we might suggest that they do some voice work with somebody. In saying that, actors working in their own accent is optimum. And if I’m working on something set in rural Ireland, say, I will always try to get authentic accents for the supporting parts, which means the actors can be even more truthful.

What’s the best Irish accent I’ve heard from a non-Irish actor? Well, I auditioned Benedict Cumberbatch for a film in 2007 and he did a spot-on Irish accent. Ever since then I’ve been determined to cast him in something.

English actor Tom Glynn-Carney’s Irish accent in Rialto is another flawless example. He immediately embodied the role in the audition and, again, his accent is spot on.

Before Covid, our process had moved into the realm of self-taping. Actors were putting themselves on tape and sending in the tape, which was a massive shift from setting up real-life auditions. We are now all totally au fait with meeting online which allows us casting directors to broaden our scope and include actors in the process no matter where in the world they live.

The challenge is that there is no casting director or director there to give the actor notes, so they’re making their own decisions. And I think we have to remember that the actor is working in isolation when we look at self-tapes.

Now, because of Covid, we do our second-round auditions on Zoom. It’s great to be able to do it but there is no substitute for being in the same physical space as a person. And I think we have to be careful not to lose sight of that.

When you work in casting, your raw material is human beings and that is something that you have to learn to deal with early on in your work. Actors are incredible — they’ll come in and audition for way more roles than they will ever get. And they’ll give all of their creativity and talent to that audition for nothing, voluntarily. And I think that’s very generous and very valuable.

Auditions can be intense and actors can sometimes get very lost in the moment. When I worked with Maureen, we had an actor in the room who was asking her to slap him. And Maureen was saying, ‘I am not going to slap you!’.

I’ve also had situations with lead actors who have already been cast. They can be quite bossy to the auditioning actors, which is an absolute no-no. The only person who should direct the actors is the director.

Anything that is tangible or changeable, I would absolutely offer advice on. I’ve often said to an actor, ‘You need to get new headshots. These don’t do you justice’. There’s no point coming in with a really glamorous headshot if you don’t look like that.

Do I think the work of casting directors should be recognised at the Oscars? Yes, definitely. A casting director is a core collaborator on a film as much as anyone else. We’re one of the first people to actually discuss a project with a director.

When you look at the list of nominations for the Best Picture Oscar this year, all of those films could be nominated for best casting. The Trial of the Chicago 7 has some really interesting casting choices. And then you have the incredible casting approach taken by Nomadland, which mixes actors and real people to great effect. I think a casting award should reflect the job. Who is breaking new talent? Who is thinking creatively and casting with flair?

It’s not that casting directors decide who will be in the film, because they don’t. Directors and producers decide. But we are very involved in offering options, consulting and interrogating decisions about who gets cast.

Our own creativity and our own taste and ideas come to bear on the film. And I think we have as much creative impact as any other department.”

As told to Katie Byrne