The evening reception featured the Hamptons String Quartet playing “Sunshine of Your Love,” Peking duck that Chinese chefs sliced and folded into soft pancakes with hoisin sauce, a sushi bar (sushi is to baby-boomer-sponsored bar mitzvahs what chopped-liver molds were to their parents’ generation), and, hovering smack in the middle of the room like the mother ship in Independence Day, a three-tiered “Tuscan Table,” a concept Harriette claims she invented, that would surely have the good citizens of Florence scratching their heads in disbelief. The bowerlike structure spirals toward the ceiling: fried calamari, baked stuffed clams, and eggplant rollatine, buttressed by copious quantities of focaccia.

And those were just the canapés.

“We did a medieval bar mitzvah last May,” Harriette says, leading the way through a black-lighted tunnel filled with streamers and blinking strobe lights toward the pièce de résistance, the dining room itself. There, life-size figures of the Queen of Hearts and the Mad Hatter, among others, gaze down upon exquisitely decorated tables featuring such touches as miniature porcelain bathtubs serving as olive boats.

“Medieval?” I inquire. It doesn’t sound especially festive.

“Say ‘Renaissance,’” Harriette replies. “It was my idea. I have to read the client. You have to know what her home is like and what her son is like.”

Back in the cocktail area, we run into Alexis Waxman, the bas mitzvah girl, who an hour earlier has delivered a moving speech at the synagogue about how a childhood fascination with Anne Frank sparked her own search for her Jewish identity but who now seems to be disoriented by all the glamour. Harriette shows Alexis the “sign in” board -- a staple of bar and bas mitzvahs where friends can offer written congratulations -- except that this one is six feet across, made of mirror and Plexiglas, and features a model of the New York City skyline.

(“I didn’t know what to say at that point,” Alexis recalls later. “I was completely amazed. It was like a dream.”)

As bas mitzvahs go these days, “Alexis in Wonderland” could be considered staid. Lee Tannen, whose Andrew Lloyd Webber-like efforts include “Mollywood,” “Jesse on Broadway,” and “Logan in the Sky With Diamonds,” recently created a bas mitzvah entitled “Absolut Erin” at the Americas Society on Park Avenue. Erin, the bas mitzvah girl, hadn’t developed a premature taste for martinis. She just loved the ads.

“The theme is the big thing,” says Tannen. “And the theme has to be different from the other 85 that you’ve gone to.”

Despite Harriette Katz’s authority on all things culinary -- one of her business cards identifies her as the “Conseiller Gastronomique des États-Unis” -- she is but one cog in the elaborate bar mitzvah-making machinery. And as far as the bar mitzvah boy or bas mitzvah girl and their friends are concerned -- kids who wouldn’t recognize a caramelized onion pierogi with horseradish sauce if it hit them in the face -- Katz is by no means the most indispensable cog.

That distinction goes to the folks who supply the laser-tag games, the wax hand-sculpture vats, the computer that morphs a boy’s image with his girlfriend’s to show you what their offspring would look like, the dog-tag-stamping equipment, the music-video studio, and the mobile photo-processing center that allows you to put a guest’s picture on everything from mouse pads to a Rice Krispies box, his face replacing Crackle’s, thus creating a bar mitzvah souvenir for the ages.

The galas seem fueled by -- in no particular order -- parental pride in a child’s formal admittance into the Jewish faith after years of rigorous study, a surging stock market, the impulse to celebrate Jewish success in America, one-upmanship, and, perhaps most of all, the desire to create an unforgettable experience for jaded 13-year-olds who may have been to a bar mitzvah luncheon at Tavern on the Green that afternoon and a blowout at the Rainbow Room the night before.

Greg Telleri, a former Club MTV dancer considered perhaps the hottest emcee on the bar mitzvah circuit -- “The emcee is king,” Lee Tannen proclaims -- received a cancellation recently because the bas mitzvah girl didn’t feel her reception could compete with those of her friends.

“She knew I was doing a friend’s bas mitzvah a month before hers where there were more games and a few more dancers,” Telleri recalls, “and she was afraid that hers would not be as good.”

Pity the children with the May and June birthdays. “At the beginning of the season, there’s a lot of enthusiasm about going,” says a mother who, like many others interviewed for this story, wouldn’t speak on the record for fear of alienating fellow parents. “But as the season goes on, there’s this frenzy to produce the unique experience.”

“Toward the end of the season, kids have been to so many parties, it’s harder to hold their attention spans for four or five hours,” says Allen Dalton, whose company, Eventertainment, provides the fun and games for what he and his partner Tom Kaufman describe as some of the more “low-key” and tasteful bar mitzvahs in town.

“We try to structure a party so there are no real lulls,” says Kaufman, though he hastens to add, “We almost always shut the games down during the candlelighting ceremony and the blessing of the bread.” The candlelighting is a ritual in which honored guests are called up to light a candle on the bar mitzvah boy’s or bas mitzvah girl’s birthday cake. Harriette Katz, for example, was extremely moved when she was called up to light candles at bas mitzvahs two weekends in a row -- at the Waxman affair and at another the previous Saturday evening at the Rainbow Room. “I became so involved with the child,” she says. “It was totally the kid’s idea.”