`We used a cowbone covered with fake blood for the chopping scene and I was saying `One little piggie went to market, one little piggie stayed at home'. . ." Being a child actor these days is a long way from The Good Ship Lollipop, especially if, like Eamonn Owens, you're the star of Neil Jordan's new film, The Butcher Boy. Unfazed by the film's murder scene, he recalls the shooting of it with gusto: "It was fun."

A well-built, fresh-faced 15-year-old, Eamonn is softly spoken and polite when I meet him in his native Killeshandra - not a bit like the precocious, unhinged Francie Brady whom he plays in the film, which is based on Patrick McCabe's award-winning novel.

Eamonn had no acting experience before he landed the part of Francie. His only performances had been as a tin whistle player with the Killeshandra Marching Band: "We marched down 5th Avenue on St Patrick's Day, and we won the competition for the best band," he says.

"But like every kid, I dreamed of being an actor." His hero is Mel Gibson; the Irish actors he most admires include his co-stars in The Butcher Boy, Stephen Rea ("he was great in The Crying Game") and Brendan Gleeson ("he was brilliant as the big bloke in Braveheart"). "I never thought I'd ever get to be on screen with them," he says, wide-eyed.

Eamonn used to be a regular cinema-goer, travelling the short distance from Killeshandra to Cavan town: "But then the cinema closed down, so we watched videos at home after that." He is the fourth of a family of five boys - his father, Peter Owens, runs a foodmart and offlicence on the main street of the town - and he was in sixth class in Killeshandra National School when Maureen Hughes, assistant to casting director Susie Figgis, came talent-scouting for The Butcher Boy, which is set (and was filmed) in Patrick McCabe's home town of Clones, in nearby Co Monaghan. Along with the other nine boys in his class, Eamonn read a scene from the film where Francie cheekily confronts his snobby neighbour, Mrs Nugent (Fiona Shaw), and her timid son, Philip (Andrew Fullerton), and tells them they can't pass him without paying "the pig toll tax". (Mrs Nugent had earlier referred to Francie's family as "no better than pigs".)

"I thought the others were better," Eamonn says modestly, recalling that first audition. The boys were told to interpret the scene in their own way. "I thought it should be funny and aggressive," says Eamonn. Maureen Hughes took photographs of the boys and a week later four of them were picked for another audition in Dublin. "My father brought me down. I was very nervous. There were boys of my age there from all over the country." They went through the same scene, this time under the eye of Susie Figgis herself. "I thought I did pretty well, but wasn't sure." With Alan Boyle, another boy from his Killeshandra class, he made it through to the last six: "I was getting very uptight at this point." And then there were four: Eamonn, Alan and two others. They were put through their paces in front of Neil Jordan and producer Redmond Morris. At the end of a "nerve-wracking" day, Eamonn and Alan were selected to play Francie and his best friend Joe. It was another day - and several try-outs with Stephen Rea and Aisling O'Sullivan, who play Francie's troubled parents - before they knew which of them had been given which part: "Alan wasn't too upset that he got the part of Joe. It's a good part," says Eamonn. The two practised their lines together and Eamonn adds quickly: "It helped having Alan in the film because it meant I wasn't the only one in our town getting the attention. My head didn't get too big because Alan was in it too. Some of my friends were worried I'd start acting like Mister High and Mighty."

Susie Figgis notes that in the initial stages of the search for a boy to play Francie: "We went to the drama schools. Because the part is so demanding and he is in almost every frame, we felt it was better to look for someone with drama experience." The long quest resulted in several finds, but most of them were "too old". It was "a fluke" that Eamonn was discovered. "I was really excited the moment I saw him." She adds: "He's unbelievable. I think he'll be much in demand in the future."

For Neil Jordan, having the right actor to play Francie was crucial: "If you can't find Francie, you don't have a movie. Eamonn is the movie. We did read-throughs with about 2,000 kids, but he was definitely the one. The way he's driven by adrenalin - Eamonn has given one of the most extraordinary performances that I've seen anywhere. "There's something in rural Ireland, which is probably disappearing now with the modernisation that's taking place. Eamonn comes from this background, which is completely unselfconscious and quite irreverent. He has huge energy, and that's perfect for the part of Francie." There has been much mention of how closely Eamonn resembles the young Neil Jordan: "Somebody said it should have been him and not Stephen Rea who played the older Francie," agrees Eamonn. "We do look alike."

Filming lasted 10 weeks and took place during Eamonn's school holidays in a variety of locations. His father accompanied him at all times, and every night they went through his lines for the following day together. Before every scene, there were rehearsals.

Figgis notes that it was very important for Peter Owens to feel comfortable with everything Eamonn does in the film: "The parent is the one who will support and help the child, so you have to make sure that the parent is happy. Peter was utterly supportive and nice about everything."

Eamonn says his parents didn't want him to pick up Francie's bad habits, like cursing and smoking. Clearly, he remained immune. He refers to the "the eff word" and did not enjoy pretending to pull on his herbal cigarette during Francie's stint at reform school. At one stage he had to wear a bonnet and sit on the knee of a perverted priest (played by Milo O'Shea) at the reform school: "When I walked on to the set in the bonnet, everyone split their sides laughing." He wasn't keen, either, on the pig abattoir scenes where Francie gets a job after being allowed to leave the reform school when the perverted priest's antics are discovered: "It turned me off bacon for a while".

All the time he was trying to understand Francie's psychology, how his mind begins to roam too dangerously in a fantasy comic-book world of aliens and baddies: "It's a turning point for Francie when his mother commits suicide and his father blames him for running away. To be blamed for your mother's death - it's enough to drive anyone mad." Eamonn found Francie's parents - the alcoholic, unhealthy father and the miserable, downtrodden mother - very different from his own secure family background, and yet "Francie is inside me somewhere, I suppose".

For scenes where he has to look particularly grief-stricken, such as when his friend Joe rejects him, he studied "the facial features" Stephen Rea used: "I liked the way he could look really sad." But there was plenty of fun to be had on the set, too, especially with Brendan Gleeson, who plays Father Bubbles, the head of the reform school: "He was a laugh," recalls Eamonn.

Gleeson was impressed with Eamonn's performance: "He was terrific in The Butcher Boy. We've acted together since then in I Once Had a Life, the new film about The General. I play Martin Cahill and he plays me as a boy." Eamonn has also just finished filming the BBC's adaptation of John McGahern's Amongst Women in Westport. After his marathon performance as the central character in The Butcher Boy, however, these other two parts seemed small beer: "I never realised that actors do so much waiting around."

What is he going to do with all his earnings? "I'm saving them up in the bank." He wants to finish school before deciding whether he is going to go into acting full-time. He is now attending St Patrick's College in Cavan, working a little in his father's shop and playing pool in the afternoons. "I like coming back to my own life," he concludes shyly.

The Irish premiere of The Butcher Boy is tonight at 7.30 p.m. in the Savoy, with proceeds going to the Beaumont Foundation and the UCD Centre for Research on Infectious Diseases. All the tickets are sold out. The film opens nation- wide on Friday.