“It was like a scene out of Close Encounters,” said Mr. Janklow to an editor from W magazine who happened to be dining at Sweetiepie last Tuesday. The bubbly new patron had dropped by his host’s table to compliment the food and mention all the attention the place was getting. “Seriously, I’m not even kidding, there was a crowd of like 50 people looking in here!”

“Now I have to ask, what was wrong with your sundae?” Mr. Janklow asked. The magazine editor explained that there had been a mix-up —he had wanted only vanilla, not no vanilla. However his roast chicken had been to die for, and he loved the décor.

The restaurant has white marble-lined floors; a long, custom-made, ’70s-style red leather banquet; a mirrored ceiling. The focus is a low-slung wide bar with white and pink stools. Mr. Janklow says the bar is his homage to the famous coffee shop at the Beverly Hills Hotel.

“Who’s back there, may I ask?” said the W editor, gesturing toward the kitchen. Back there was Humberto Guallpa, 30, of Ecuador, who has run kitchens for Mario Batali, among others. He and Mr. Janklow are currently work-shopping a club sandwich.

“The only thing I said to him is, ‘Look, you have to understand that in my eyes, you’re a cook, you’re not a chef,’” said Mr. Janklow. “And I mean that in the highest possible respect. It’s all about the people who come here; this is not about you showing off and building architecturally impossible foods. It’s about making the best grilled cheese sandwich in the world, the best chopped salad. And he totally got it.”

The week before, Mr. Janklow had sent Mr. Guallpa on a 24-hour tasting tour of Los Angeles coffee shop cuisine. Mr. Janklow sees a sharp distinction between coffee shop and diner food. Sweetiepie offers a scoop of tuna in a tomato, candied bacon, pancakes, mini-burgers, an expensive steak and a cheaper steak. “We don’t serve meatloaf and mashed potatoes here,” he said. 

Previous to Sweetiepie, Mr. Janklow, 41, worked as a literary agent at his dad’s shop, Janklow & Nesbit—he sold a lifestyle book by Gwyneth Paltrow earlier that day—and acted as a producer of films based on some of his authors’ books. He also published essays on such topics as the merits of long hair on men.

“I feel like I’m in the storytelling business,” he said. “I feel like Sweetiepie’s a story, I feel books are stories obviously, movies are stories—I can find a story in anything. That’s how I manage to keep it all going—and I write articles for Men’s Vogue and whoever will have me, basically. So it’s all storytelling in some capacity, but I do have four jobs. I’m hoping one of them will take off.”

“Storytelling business” is a phrase he’s probably heard tossed around since childhood. His father, Mort Janklow, founded Janklow & Nesbit, which represents authors such as Malcolm Gladwell, Al Gore and Michael Moore. His mother is Linda LeRoy Janklow, daughter of filmmaker Mervyn LeRoy, who produced The Wizard of Oz, and granddaughter of Harry Warner, who cofounded Warner Brothers. Then there’s Luke’s late uncle, restaurateur Warner LeRoy, who operated Tavern on the Green and the Russian Tea Room.  

Mr. Janklow grew up on Madison Avenue in what he likes to call “Woody Allen’s New York.” Instead of Chanel and Etro and Armani, the Upper East Side was dotted with personality: Lehman’s Hardware, the local five and dime, a store called Lucidity that sold nothing but crap made out of Lucite. At age 9, the mighty Luke would set off on his own, skateboard in hand, to visit his favorite guitar shop downtown and on the way maybe drop by the Viand coffee shop on Madison and 61st for a cheeseburger from the friendly Greek guy. Last time Mr. Janklow checked, he was still working the grill! 

“It was much more fun and interesting, crazy and more flavorful,” he said. “What’s happened now, like with everything else in the world, it’s become homogenized, it’s become chains all over. There’s a certain thirst for moneymaking—which we’re all paying back for now—and you can just physically see it. It wasn’t like that when I was a kid, it was much more mom and pop, there was a shoe store, a locksmith—it was more of a smaller scale, European-type town.”

Mr. Janklow has been in the West Village neighborhood since he graduated Dalton. He did two years at Wesleyan University but was commuting the whole time. He decided to pursue music, dropped out, and set off on a decade-long road trip—a small apartment on Fourth Avenue served as home base. He could never come up with a good band name. Darlahood was the one that stuck longest. Toward the end of it, he crossed paths with Julie Daniels, the zany, hippy-chic brunette from Beverly Hills he’d met a decade earlier. Turned out she’d become a rocker, too; they shared a publicist in common.

Before long they were another happily married pair of retired rockers in the West Village and the parents of a bouncing boy, August, now 6. They purchased a $4.5 million townhouse on West 12th Street from André Balazs and ex-wife Katie Ford. Mrs. Janklow began renovations. 

Mr. Janklow, meanwhile, had discovered a talent for lit-agent-ing. “People always ask me if I read a lot and it’s like, ‘You know what? I read a lot, but I don’t read that much, because it’s like, if you’re in a car and you’re listening to the radio, how long do you give a song you haven’t heard before, before you flip the station?’” he said. “I know in about two seconds if something is good or not. And I’ve never been wrong so far.” In ’07, Gawker voted Mr. Janklow the hottest straight man in book publishing. A little while before that, he got HarperCollins to pony up $1 million for Anderson Cooper’s memoirs. 

Mr. and Mrs. Janklow soon concluded there was no cool restaurant in the West Village where you could bring your kid, even their beloved Waverly Inn. In particular, Mrs. Janklow had in mind the places her parents used to take her growing up in Beverly Hills. The sophisticated yet pedestrian, slightly theatrical restaurants, which are unique to Hollywood and function not only as an extension of the industry but also a local haunt where a kid can delight in the glinty surroundings and a grilled cheese and Mommy can feel glamorous sipping vodka.

“I realized that there was no place to go for Easter or Mother’s Day or just for a day out; there was no place to go with my son,” she said, between puffs of a cigarette on a recent afternoon in the back room of Sweetiepie, where a mural of Mrs. Janklow’s own design festoons the wall. A Star Wars storm trooper here; a zebra on the hood of a hot rod there. Mrs. Janklow had her dark hair parted Joan Baez–style, and wore all black, a black faux fur coat on top. “It just got me thinking that when I was a kid, growing up in Beverly Hills we had those places—and they weren’t places like kids’ restaurants, they were just places that were theatrical because back then most of the restaurants were done by set designers. So you’d go to the Luau and you were in a Polynesian village, not some cheesy low-budget place—it was actually done by the real deal. Or you would go to Trader Vic’s or Chasen’s and it was glamorous. And as a kid you went into this sophisticated setting that was also childlike.”

They got the space on Greenwich Avenue about a year ago. Getting things just right has added some miles onto Mr. Janklow’s Vespa.

“I joke with Julie that she’s the director and I’m the producer of this place,” said Mr. Janklow, who seems to have wisely chosen to focus on the food.

In the last month or so, the couple has filled up Sweetiepie with numerous private parties—Ralph Lauren hosted a tea; the model Tamzin Greenhill had her baby shower there; most recently Lucy Sykes held her 39th birthday in the back room.

“There is a slightly nostalgic quality, a childlike quality to it, but it also has an adult decadency about it,” said Mrs. Sykes’ husband, Euan Rellie, noting that while the women ate salads, he enjoyed the spaghetti and meatballs. “People drank quite a lot, which is always a good sign.”

“If we had our dreams come true, it would be a place that would be thought of alongside Leo’s Coffee Shop on Madison Avenue,” said Mr. Janklow. “With the black smoked glass windows and tablecloths and waiters in bow ties, and Mrs. Astor having a tuna sandwich with her girlfriend for four hours and talking.”

He added that once things were established, Sweetiepie has great potential as a brand.

smorgan@observer.com