The dialect was a snap for Federico Castelluccio, who was born in Naples and spoke Italian at home even after his family moved to Paterson.

And playing Tony Soprano's brutal imported enforcer, Furio, was an exciting challenge for the soft-spoken and unfailingly polite actor.

But the scene in Artie Bucco's restaurant in which Furio had to make mozzarella (his feigned specialty) while a cigarette dangled from his mouth -- now, that's another story.

"They were hyping me up to be a great mozzarella maker," Castelluccio says, laughing. "I come in and I'm making mozzarella with this cigarette. I don't smoke, and I had to hold my breath the whole time. If I were doing that scene underwater, it would have been easier for me."

In the end, Castelluccio came across just fine. The guy is, in fact, making quite an impression this season. Michael J. Fox came up to congratulate him on his work at Sunday's Screen Actors Guild Awards in Los Angeles (where "The Sopranos" picked up three major awards). And viewer postings on HBO's "Sopranos" Web site seem to indicate that he's the show's new sex symbol.

"I haven't seen it myself, but a lot of friends and people that know me have been telling me about what's online," Castelluccio says.

The actor -- whose family migrated from Naples to Paterson in 1968, when he was 3 1/2 -- couldn't be more different from his chilling character. Besides his pursuit of acting over the past dozen years, the gracious Castelluccio is a successful artist, whose paintings -- many of them with religious themes -- hang in private and public collections and have been exhibited in New York City galleries.

"My style is contemporary realism," says Castelluccio, who lives in Morris County, where he has a studio. "I studied early Italian and Dutch Renaissance painting, and my techniques are derived from that era, but I use contemporary figures.

"I was up till 6:30 this morning painting. A Madonna and child. A small painting," says the actor-artist, whose work was featured in the February 1999 edition of American Artist. "I'm creating an 18th century tabernacle frame for a collector. He owns about five of my paintings now."

Castelluccio's warm, artistic nature didn't prevent him from nailing down his sadistic character.

"Furio's a very dedicated soldier. He's got a sense of humor about things, but he knows when to draw the line," Castelluccio says. "He definitely is not happy that he has a woman boss [back in Italy], so he's very intrigued by how things are run in America. He's taken a liking to Tony."

The character has already shown himself to be a fearsome Mafia messenger. In one memorable scene, Furio wreaked havoc in a whorehouse whose owners were shortchanging the Sopranos on their cut of the business. After attacking several people -- including the owner and his wife -- with a baseball bat and a metal pipe, Furio casually shot the husband in the kneecap, then punched the wife, and spat on her for good measure.

How's this guy so convincingly savage?

"For the most part, I use mainly my imagination," Castelluccio says. "I also use some of the things I went through when I was a young kid in Paterson. I wasn't cantankerous. I didn't start fights. I just kind of ended them before they started, but in the neighborhood I grew up in, you had to know how to fight."

After graduating from Passaic County Tech in Wayne, Castelluccio went to Manhattan's School of Visual Arts on a full scholarship.

But acting, he says, is "something that has been with me since I was a child, and I've always known that I was eventually going to take that path."

He took his first step down that road in his last year of college.

"I felt that I was at a certain plateau with my work, and I just moved into acting at that point," Castelluccio explains.

After talking his way into an extra role on the 1988 movie "Crocodile Dundee II," he went on to do theater in New York and New Jersey.

It was his girlfriend, model Stephanie Norwood, who spotted the "Sopranos" casting notice in the publication Backstage.

"She said, 'You'd be perfect for this,'" Castelluccio says. "I wound up getting called in for a New York boss. But I read the breakdown, and I knew I wasn't right for it. I got the audition, they put me on tape, but I never heard anything back. And when I saw who they chose, he was absolutely perfect."

Eight months later, though, Castelluccio got another call -- for the role of Furio, who showed up this season in the fourth episode, in which the Sopranos traveled to Naples to clinch a business deal. Tony persuaded his sexy female Italian counterpart to give him her best man -- Furio -- on loan.

"When I first auditioned, it was for a scene that took place here in America. I had no idea that they were going to Italy until after I was hired," Castelluccio says. 

Speaking Italian was one of the role's requirements.

"It not only had to be Italian, it had to be the vernacular of Naples, my hometown vernacular," says Castelluccio, who knew, from having "religiously watched" the series last season, that Tony Soprano's family hailed from Avellino, which is right outside Naples. "I have to thank my parents for wanting us to retain our language. We spoke English outside, but we only spoke Italian in the house."

One of the many thrills about being on "The Sopranos," Castelluccio says, is working with James Gandolfini, one of his longtime "heroes."

"Oh, my God, this guy is so incredibly generous as an actor. I'm learning a lot from him, too," he says. "I've been around for awhile, but this guy ... he's just a consummate actor."

HBO announced this week that "The Sopranos" was renewed for two more seasons, but Castelluccio, needless to say, can't divulge if he'll be among those returning.

In the meantime, though, he's pondering other offers (including the lead role in an independent film), continuing to work hard on his art, and learning to contend with sudden fame.

"I've been noticed all over in New York City and New Jersey," Castelluccio says. "One day, I walked into Macy's in Willowbrook [in Wayne], and I got mobbed."

Despite the fact that security arrived on the scene that day, he adds, "It's a great feeling. I love joking around with the fans. New Jersey has never been shown on film like the way it is in this show."