For most actors, a co-starring stint in "Harold and Kumar Go to White Castle" is not the way to get the lead in a major drama. What proven director making a low-budget movie is going to cast an actor who has spent his career training audiences to think of him as the Cheetah-riding hero of a stoner road movie?

Yes, but we're forgetting something. Hollywood filmmakers have kids, too, and they see the same movies as everyone else. When Kal Penn was throwing everything he had into getting an audition for the lead in Mira Nair's "The Namesake," which opens at The Michigan Theater tomorrow, he didn't count on having an insider who was already doing most of his work for him.

"Mira's son loved 'Harold and Kumar,' " Penn said, "and he kept telling her to she had to audition me. . Eventually she listened."

It was a fortunate break for Penn, who had read the Jhumpa Lahiri novel on which the film is based and tried to buy to rights so he could develop it himself. He was told soon after that Nair, the director of "Vanity Fair" and "Monsoon Wedding," had beat him to it.

Penn said he tried to contact the well-liked director repeatedly but didn't get anywhere until her son intervened.

"After that, we met, and it went from there," he said.

In the film Penn plays Gogol, the American-born son of Indian immigrants who grows apart from his parents as he ages. It opens years before Gogol's birth and continues into his mid-20s, focusing most prominently on his post-high school, early adult years. The film has opened to adoring reviews and strong numbers in its platform release.

Amid the movie's heavy press attention that has championed it as an affecting portrait of the immigrant experience, Penn cautioned against letting this broad and large-scale story of cross-generational cultures cloud perception of Gogol, who Penn said never shares his parents' struggles.

"Gogol always knows who he is," Penn said. "He doesn't have the same identity struggles as his parents. He doesn't change the way they do; he struggles with his parents and other people who don't understand him."

Penn said the key to Gogol's transition is the time just before and after his college years. Although the film largely imagines Gogol's time at Yale off screen (one of the heftiest sections of the novel), Penn said he found other ways to reflect his transition from a teen to a Yale graduate.

"People at Yale know they're among the leaders of their generation. There's a real sense of that there," Penn said. "Gogol is a nice guy, but he also changes there, and I visited New Haven and got a sense of how that changes him."

Though Penn is now at work on the sequel "Harold and Kumar Go to Amsterdam," he said after his experience on "The Namesake" he will continue to seek more complex characters.

"A movie like 'Epic Movie,' that's fun, but 'The Namesake' is the most rewarding thing I've done," he said. "It's definitely the best movie I've done."

The film's brewing success can't hurt, but fate seems to be on Penn's side. Mira Nair's kids must play with Steven Spielberg's kids, right?