Even before Penn auditioned, he had known about the script and was a tad sceptical that a comedy featuring two Asian-American characters would ever get off the ground. "I met the writers at a friend's birthday party and a mutual friend introduced us and said 'These guys wrote a script starring an Indian guy and an Asian guy.'  And I was 'Oh really?  Yeah sure, I'll see what's up.' Kind of like, 'Hey, dude, nice to meet you.' I was like, 'Hey, so what's your script about?' And they explained it to me. I'm like, 'Do they have accents?' They're like no. 'Oh, good luck getting it made.' And they were like, 'No, we're sending it out in two weeks. It's going out on the market. Do you want to read it?' I'm like, 'Of course I would love to read it because it sounds like a fantastic idea, but maybe we should talk about getting it financed.' They're like, 'No, we want to sell it to a studio.' Like yeah, all right, you're first time writers, huh? Because I was so cynical based on roles that I've taken in the past and what's out there. Then I got the script a couple days later, read it and called them up and I'm like I'll do whatever it takes to help you make this movie. A couple days later they sold the script. I'm still amazed, but I really think that their writing kind of speaks for itself and why the film was made because the writing supersedes anything else."

On the surface, Harold and Kumar sounds like a conventional follow-up to the director's critically maligned, Dude, Where' s My Car? Here two stoners head on a road trip in the dead of night, for no reason than score a hamburger in an East coast burger chain, White Castle. En route, they encounter many an outrageous adventure while growing up in the process. White Castle may be uniquely indigenous to one geographical section of the United States, but Penn says that this real-life burger chain is symbolic of what is unique about this country. "It's the type of place that's always crowded after one in the morning.  I grew up in Jersey, so there were a couple of White Castles around and I never saw it crowded during the day.  I think the appeal is that they' re tiny, square nebulas of burger that’s.  They're little and you can eat as many as you want."

Penn strongly feels that even amidst the movie's most outrageous moments, Harold and Kumar goes beyond the norms of the conventional teen movie. "While it's a teen movie, you have characters that we haven't seen before, and not just for physical reasons, but also their back stories.  These two guys went to Columbia University, they're Ivy League Educated guys, one's an investment banker, and one's applying to med school.  So automatically, it's not the typical dumb leads of a teen movie.  Then on top of that ethnicity doesn't drive the plot of the film and it's also not ignored by the story, which I think is completely groundbreaking and more interesting for an audience to watch. So within all the fart jokes there's a lot of social commentary that makes it a little bit smarter and a bit different."

For Kal, whose last major movie role was in the forgettable Van Wilder, he was excited to be playing a character devoid of stereotypical accent and mannerism. But Hollywood still has a narrow perspective when it comes to ethnicity, says Penn. "When you're training to be an actor, you don't sit there and go 'I'm training to be an ethnic actor.'  It's only when you get to Hollywood and you walk into an audition and they say the most absurd crap to you, that you realize you're being put in this little category." Once asked to get a turban and speak more Indian, Penn says that to some extent, nothing much has changed. "For me, it's changed, but I speak to other actors who deal with the same thing. I hesitate saying it's changed because I know it has for me individually and the hope is that if a film like this, makes money, this movie is doing everything wrong according to a traditional studio formula. I think the studio formula's archaic but it's putting two men of colour who have been asexualized for years in film as the lead roles. It' s making the characters smart in a movie that should be dumb and it's been testing well, so automatically by testing well, it's proving other studios wrong.  The hope is that if the movie makes money, the people that make movies will go: 'All right, so we can put a woman in a role that was originally conceived for a man. We can mix up the pot and reflect reality a little more and thereby tell a better story.'"

Penn wanted to act since age 8 when he saw Mississippi Marsala, but as the son of immigrants, his parents were far from happy with his choice of career.

"My dad came here with $12 and a $300 loan that he took out to pay for school. In his pocket. To hear the stories of what he went through in order to establish himself and set up a family is amazing. I think their first reaction was why would you want to do something that's not stable because we did something that was stable and even within that stability, it was so hard to set foot. They are also aware that they came to fill a labour shortage. There was something called the Asian Exclusion Act that was lifted in ' 65 I think because of labour shortages in medicine, engineering and fields like that. So they came with very little money and also came with an opportunity to fill a labour shortage. So all of those things combined and they're like A, it's not a stable career, and B, we turn on the TV. and we don' t see people that look like us, so why would you ever want to go into a career like that knowing that the odds you're going to be up against are so great?  That was their first reaction.  But as they saw that it was something I was very passionate about, I wouldn't say they were totally encouraging, but they weren't discouraging." 

These days, Penn's parents have reason to be optimistic, as he is out to prove that ethnicity needs not drive a Hollywood script. It 't with Harold and Kumar, nor with his next project, Son of the Mask. "That's a very over the top script and was actually kind of fun to work on. It's $100 million budget. I don't know how you spend that, but I saw how you come close. ''s live action with a lot of animation and special effects in it, so every character is not one dimensional, but exaggerated. Jamie Kennedy plays The Mask and there are two or three guys that work at this animation studio with him, and I play this guy who is like an animator, special effects technician." Penn has also completed work on A Lot Like Love. "It's a romantic comedy with Amanda Peet and Ashton Kutcher which is also coming out next year. Ashton and I play characters that start an internet company when we graduate from college, selling diapers. The joke is that we're 22 and have no idea how to sell diapers, but it seems like a secure business model because people are always popping out babies. So it's like well, there's always going to be a demand for diapers and if we're the first ones to sell it on the internet, then we'll totally make money."

The future seems rosy for Kal Penn, and not a turban or accent to be found.

Harold And Kumar Go To White Castle opens on Friday.