From Brooklyn to Ballinasloe, the iconic image of eleven men taking tea above the New York skyline has enchanted countless generations, but who were the Men At Lunch? That's the question that Irish brothers Eamonn and Sean O'Cualain set out to answer.

Little did they know that their little documentary about the search for the construction workers would become a smash hit, and even get a nod from the IFTAs. We caught up with them earlier this week to find out a little bit more about the film...

So lads, we've heard that this adventure, like many before it, started with story told over a pint in a pub in Shanaglish, Co Galway. What was it about this particular story that inspired you to make a documentary?
It was actually over a coffee and a toasted sandwich, we were in Whelans pub in Shanaglish near Gort in Galway and we saw the famous photo on the wall and a note from Pat Glynn, the son of a local emigrant who claimed his father and uncle in law were on the beam. By the time we had left the pub, the owner Michael Whelan had given us Pat Gynns number, so it was simply a chance discovery.

Patrick O’Shaughnessy and Patrick Glynn claim that their fathers are two of the men having lunch. When you first started looking into their claims you found it would be almost impossible to prove them, so what made you keep going?
We had originally intended for the film to investigate the claim of the O’Shaughnessy and Glynn families, but we found out that no records of the construction survived, that no information on the men, or the photographer existed. We realised the film's story had to change. It was now to become the untold story of the most famous image in the world, the mystery of the eleven men on the beam and the great immigrant struggle.

You've got the great Fionnuala Flanagan providing the narration in English and as Gaeilge! How did you manage to get her on board and what was it like to work with her?
We contacted Fionnula’s agent who passed on a draft of our script to Fionnula. She liked it, and the story we were telling fascinated her. It was then just a matter of finding a time in her schedule to record her narration before its premiere. She was a joy to work with, she really enjoyed the Irish language telling of the story.

So, the documentary was first shown in Ireland last year. What was the response here at home like?
The film received its premiere at the Galway Film Fleadh, we had a lunchtime premiere and it was sold out, a great reaction from all. We did a 2012 recreation of the image in Eyre Square and those images were seen all over the world. From there we got an invitation to TIFF, Toronto International Film Festival which was great. We had 3 sell out shows and from there the demand for the film worldwide has been overwhelming. International audiences love the Irish connection and the mystery of the photo but also have a great understanding of the struggle all immigrants had when they arrived in America. TG4 have delayed the broadcast of the film to St Patrick’s day this year, without their help this film would not have been made.

I suppose an IFTA nomination is as ringing an endorsement from the home crowd as you can get! How did you feel when you found out the documentary was nominated?
We were delighted to get the nomination. Awards are strange - you would love to win on the night, but if it goes elsewhere you dont beat yourself up about it. We have two IFTA awards from previous years, but on both occasions we could not attend as were on a film shoot elsewhere, so it would be great to finally get one in person.

When you were sitting in that little pub, looking at the iconic photo, did you ever think that Lon sa Speir would take you so far?
Driving home that evening we never felt the film, as it we saw it then, would get such a reaction. It began life as a one hour TV documentary to trace two Galway families and their claim to a famous photograph. When we realised no research had been done to help us - it did become something else and a film we knew would have a strong appeal all over the world because the themes of the image are universal.

Obviously you are brothers. What was it like working together on such a fascinating and far reaching project?
It worked very well for us, working so closely can only help a project reach its potential.

So, when it comes down to it, what do you hope audiences will take from the documentary?
We always intended for the film to be very much a reflection of all the themes and emotions illustrated in the photograph. It is a celebration of what ordinary men from Ireland and Europe built when they arrived in America. I hope people feel a sense of pride in what these men achieved and that the next time they visit Top of the Rock in NY or see the NY skyline, they do so with the knowledge that Irish hands were very much part of its construction. It will also resonate with people and families who have just left or are leaving the country to work abroad. No matter where we live we can achieve and aspire higher.

And we know that many of the men still have to be identified so tell us, is the adventure over or will we be seeing more of the men on the skyscraper?
Very much so, Cuid a 2 is very much in the pipeline - since the films release we have received a lot of new material and claims from families all over the world as to who the men might be. The identity of the photographer has also become a mystery because of information revealed in our film and that something we want to look into. We never intended to be the 'go to guys' for the photograph but we have become that, so for the forseeable future the eleven men on the beam are very much part of our lives.

Men At Lunch is currently showing in Irish cinemas.