Of Mice and Men” may be a particularly American tale, but Irishman Chris O’Dowd — who stars with James Franco in the Broadway revival that opened April 15 — still knew the story well.

“Oddly, Steinbeck is quite big in Ireland,” O’Dowd said at the afterparty at Gotham’s Plaza Hotel. “I think there’s something about the American Dream that resonates. So many of them have tried it!”

He added that the way to approach an iconic role like Lennie, the gentle giant who doesn’t know his own strength, is not to think of it as iconic. It helped that he had read the novel but never seen a production of the play or a film adaptation: “Maybe they showed the movie to us in school, but I didn’t pay attention,” he joked.

Franco, who plays Lennie’s pal George, talked up the instant rapport he shared with O’Dowd. The two actors had never worked together, but you’d never know it. “Nicholas Cage saw the show and said, ‘You must have known each other for a long time,’ ” said the thesp, surrounded by his extended family at the Plaza.

He’s enjoying the energy each new audience adds to his performance night after night, and savoring the differences between film and the stage.

“Not only do you have to learn your lines, but these lines are written in stone,” he said. “This is a classic play. They are on our asses about everything. If I say ‘That’s not nothing’ instead of ‘That ain’t nothing,’ they’re on me! That’s a new thing for me. It’s like a zen kind of practice where you’re aligning yourself with the text. It’s kind of nice, because I’ve also worked at other other extreme. Like when I do a movie with Seth Rogen, anything goes!”