You're in a fancy restaurant, slicing your way through the juicy filet mignon, when a guy at the next table leans over and says:

"Excuse me, but that looks delicious. May I have a taste?"

You hand him your plate. He takes a bite . . . "Hey, that's great" . . . and passes your steak to his date.

Chances are you've just met Elliot Jaffa, 36, a self-proclaimed Chutzpa Master who -- in addition to "the restaurant taste test" -- has used his colosal gall to:

Throw a bar mitzvah party for his mustache.

Gain entrance, free, to a $250-a-ticket theater benefit.

Crach countless Capital Hill parties.

Get to the front of numerous long lines.

Direct snarled traffic after concerts and sporting events.

Meet stars such as Peter, Paul and Mary and see their concerts free . . .

Formerly a doorman for the Apple Tree -- "when it was in its heyday," he stresses -- Jaffa holds a doctorate in education and is now a self-employed behavorial psychologist specializing in aggressive marketing, motivational management, weight reduction, positive parenting, smoking cessation, bartering, assertiveness, health promotion . . . you name it.

"I've got so much chutzpa," he boasts, "I've decided to teach it." With characteristic nerve, Jaffa not only charges $10 for his 90-minute "Chutzpa 101" session through Open University -- he asks participants to bring a bottle of wine and some hors d'oeurves. His private chutzpa lessons run $55 an hour.

A dozen people showed up for his first Beginning Chutzpa class (he does not plan an advance version but will repeat the elementary course). Among them were Chick Anderson, a 30ish stock broker "into assertiveness," Jim Whitney a "kind of shy" 59-year-old scientist and Phyllis Wexler, 30, an Alexandria homemaker whose one brush with chutzpa -- conniving to meet Gene Kelly -- resulted in "the best three minutes of my life."

Although "You see the word chutzpa all the time," Jaffa told the group assembled in his Arlington living room, "there's a lot of confusion over what it means."

Perhaps because the word is Yiddish, he conjectures, it is commonly thought to mean anything from "tenacity" to "unmitigated gall."

"After talking with my rabbi," he says, "I've boiled the definition down to two words -- nerve and directedness."

"Chutzpa is having the guts to go after what you want. It is the epitome of assertiveness."

A "chutzpa person," Jaffa says, is someone who follows the basic principle he uses in his psychololgy practice: "Tell me what you like, tell me what you don't like, tell me what you want, tell me what you don't want. Say it, don't think it.

"With chutzpa you assert yourself. You don't wait around wishing for something. You go and you do it. And doors will open."

Jaffa's Chutzpa Ground Rules: "Don't do anything illegal, don't hurt anyone and don't come across as obnoxious."

About Jaffa's own chutzpa examples possibly stretching some of those rules, he says, "You've got to follow your own ethnics."

"For example, you go out to dinner, tell the waiter it's your date's birthday and the whole kitchen comes out singing with a big cake -- but it's not her birthday. Some people may think that's funny, some people may think it's unethnical."

Jaffa's class is inspired at least one woman to use her chutzpa potential.

"I'm really dying to go take pictures of the Congressional Black Caucus fashion show and dinner," 26-year-old secretary and free-lance photographer Joyce Thompson told the group. "But I've been embarrassed to try it without the credentials."

After the class vowed to go, and did. "It was terrific," she said the following week. "I was the only female there with cameras around my neck. I hooked up with another photographer and no one said boo.

"I got some great shots, and made some connections with models who wanted photos and with designers. The class gave me the nerve to try it, but the chutzpa was all on my own."

Anyone can cultivate chutzpa, says Jaffa, if you:

Look like you know what you're doing. "Walk into a room like you own the place. If you walk into a broom closet, stay there 20 seconds, then walk out like you've been someplace important."

Don't panic. "If someone asks you for a party invitation, coolly search every pocket. Be dressed perfectly for the occasion, and gain their sympathy because you've left it at home. If that fails, get someone to take you in, or find a back door, grab a glass and act like you've been there all night."

Drop names. "When you're in the Giant, mention Izzy Cohen."

Practice. "Walk up to someone in a long line and say 'Excuse me, I'm a type-A person who hates to wait in lone lines. Can I get in front of you?' Do it when you don't even want to go in, and when you get to the front, leave."

Talk low and slow. "Carry authority in your voice."

Take pride in your chutzpa. "Who cares if your boss walks by while you're out telling jokes to a crowd on the street? Don't be a closet chutzpanik."

If you begin to sweat, Jaffa says, "It's too serious to be chutzpa. Chutzpa is a game you play with yourself that says, 'hey, life is fun.' It's trying out risk-taking behavior. The worst that can happen is someone will say no." (A word Jaffa admits, he has heard once or twice.)

"Most of my failures have been in being direct with women. It takes chutzpa to ask a woman 'Would you like me to know your phone number?' But a lot of women nowadays appreciate that kind of directness."

Although he says he's never been thrown out anywhere or arrested, he was once "out chutzpaed."

"I had called up for tickets to an event saying I was a reporter for some big magazine, and they said there'd be an envelope for me at the post office. Inside the envelope was a note saying 'Nice Try.'"