Oliver Cotton
Oliver Cotton
© Dan Wooller for WhatsOnStage

I started out working with Laurence Olivier's company in small roles and then with the National Theatre Company, on and off, which were both great periods in my life. When I worked with Olivier I was very young and he was in his prime and I was awe-inspired. I used to watch him from the wings and wonder how he was doing what he was doing. It was a different period of history, really.

I've written more and more over the last 20 years, much of it has never been seen. Some of it is stuffed under the mattress, some is made with a writing partner – for TV and stuff like that – but there are some plays which haven't been produced because they just aren't very good. Some of it turns into other stuff later on. I have a couple of films I feel very strongly about but the money couldn't be raised and I have written a play on Bach [The Score] which had a reading at the Park [last month] and it went well but I need to do some more work on it, so I would like that to be done.

In the case of Dessert, Trevor Nunn, who I work with a lot, he read it and said he wanted to do it straight away, which was encouraging. It would be like if you wrote a classical piece of music and Simon Rattle said he wanted to conduct it, it is amazing. Trevor is very clever and experienced at pushing an actor in the right direction, and I love working with him.

I do like classical music. I play classical guitar and for five minutes I once had an ambition to be a classical guitarist. I went once a week to lessons for seven years, I think, but if you don't play every day... I'd have been a [American composer, conductor, and pianist] John Williams or a [English virtuoso classical guitarist] Julian Bream, that was more my area. I am very interested in classical guitars. I have two very good, expensive guitars, they are beautiful instruments. I want more, but my wife always screams at me, ‘you're not getting another guitar'.

Dessert is a thriller, in a way, and I am being evasive not because I want to be coy but because you wouldn't want to talk about the main events in a whodunnit but I can tell you it is set in a big country house, at a dinner party, with people catching up on their life and then... something happens.

It is about modern life and my concerns about modern life. That is one of the underlying things. I believe communication has moved on so fast and things that would have taken weeks before you can do instantly now, so actually the way we speak to each other, the way we communicate and therefore leave other people behind is what technology always does, but that isn't what the play is about.

The play is about the growing gap between the vastly rich and extremely poor and why that gap continues to grow. Anyone who has tried to rent a flat or buy a house will realise most people's wages don't equate with the cost of living. So when you have something like the crash of 2008, you thought the stock exchange and business worked one way, then you realise people are bundling debt up and giving mortgages to people who won't be able to pay them. Society becomes a casino that only a few hundred people understand and everyone else is subject to what happens. But the play doesn't really go into that either. The play is extremely simple, actually.

This is not flannel, but the cast are truly the best cast I've ever worked with. We are very lucky to have Teresa Banham, Alexandra Gilbreath, Stephen Hagan, Stuart Milligan, Michael Simkins and Graham Turner, they are all phenomenal, all of them. I've got an incredible director and I'm hoping very much that people like it. It's funny as well.

We had our first preview last night. It seemed to go very well. These things are always a bit of a kick b*ll*cks scramble. I'm used to being on the other side, you see, and it's difficult just sitting there, watching.

Dessert runs at Southwark Playhouse from 18 July to 5 August, with previews from 12 July.