As a young waitress in a gray polo shirt set down bowls of broth, a plate of greens, and a platter of shuddering noodles, Bourdain fished chopsticks from a plastic container on the table. Obama, surveying the constituent parts of the meal, evinced trepidation. He said, “All right, you’re gonna have to—”

“I’ll walk you through it,” Bourdain assured him, advising him to grab a clump of noodles with chopsticks and dunk them into the broth.

“I’m just gonna do what you do,” Obama said.

“Dip and stir,” Bourdain counselled. “And get ready for the awesomeness.”

Eying a large sausage that was floating in the broth, Obama asked, “Is it generally appropriate to just pop one of these whole suckers in your mouth, or do you think you should be a little more—”

“Slurping is totally acceptable in this part of the world,” Bourdain declared.

Obama took a bite and let out a low murmur. “That’s good stuff” he said, and the two of them—lanky, conspicuously cool guys in late middle age—slurped away as three cameras, which Bourdain had once likened to “drunken hummingbirds,” hovered around them. Noting the unaffected rusticity of the scene, Obama was reminded of a memorable meal that he had eaten as a child, in the mountains outside Jakarta. “You’d have these roadside restaurants overlooking the tea fields,” he recalled. “There’d be a river running through the restaurant itself, and there’d be these fish, these carp, that would be running through. You’d pick the fish. They’d grab it for you and fry it up, and the skin would be real crispy. They just served it with a bed of rice.” Obama was singing Bourdain’s song: earthy, fresh, free of pretense. “It was the simplest meal possible, and nothing tasted so good.”

But the world is getting smaller, Obama said. “The surprises, the serendipity of travel, where you see something and it’s off the beaten track, there aren’t that many places like that left.” He added, wistfully, “I don’t know if that place will still be there when my daughters are ready to travel. But I hope it is.” The next day, Bourdain posted a photograph of the meeting online. “Total cost of Bun cha dinner with the President: $6.00,” he tweeted. “I picked up the check.”

“Three years I haven’t had a cigarette, and I just started again,” Bourdain said when I met him shortly afterward, at the bar of the Metropole Hotel, where he was staying. He cocked an eyebrow: “Obama made me do it.” Bourdain, who is sixty, is imposingly tall—six feet four—and impossibly lean, with a monumental head, a caramel tan, and carefully groomed gray hair. He once described his body as “gristly, tendony,” as if it were an inferior cut of beef, and a recent devotion to Brazilian jujitsu has left his limbs and his torso laced with ropy muscles. With his Sex Pistols T-shirt and his sensualist credo, there is something of the aging rocker about him. But if you spend any time with Bourdain you realize that he is controlled to the point of neurosis: clean, organized, disciplined, courteous, systematic. He is Apollo in drag as Dionysus.

“He has his mise en place,” his friend the chef Éric Ripert told me, noting that Bourdain’s punctiliousness is a reflection not only of his personality and his culinary training but also of necessity: if he weren’t so structured, he could never stay on top of his proliferating commitments. In addition to producing and starring in “Parts Unknown,” he selects the locations, writes the voice-overs, and works closely with the cinematographers and the music supervisors. When he is not on camera, he is writing: essays, cookbooks, graphic novels about a homicidal sushi chef, screenplays. (David Simon recruited him to write the restaurant scenes in “Treme.”) Or he is hosting other TV shows, such as “The Taste,” a reality competition that ran for two years on ABC. Last fall, during a hiatus from filming, he launched a fifteen-city standup tour. Ripert suggested to me that Bourdain may be driven, in part, by a fear of what he might get up to if he ever stopped working. “I’m a guy who needs a lot of projects,” Bourdain acknowledged. “I would probably have been happy as an air-traffic controller.”

As he sipped a beer and picked at a platter of delicate spring rolls, he was still fidgeting with exhilaration from the encounter with Obama. “I believe what’s important to him is this notion that otherness is not bad, that Americans should aspire to walk in other people’s shoes,” he reflected. This idea resonates strongly with Bourdain, and, although he insists his show is a selfish epicurean enterprise, Obama’s ethic could be the governing thesis of “Parts Unknown.” In the opening moments of an episode set in Myanmar, Bourdain observes, “Chances are you haven’t been to this place. Chances are this is a place you’ve never seen.”

From the moment Bourdain conceives of an episode, he obsesses over the soundtrack, and for the sequence with Obama he wanted to include the James Brown song “The Boss.” When the producers cannot afford to license a song, they often commission music that evokes the original. For a “Big Lebowski” homage in a Tehran episode, they arranged the recording of a facsimile, in Farsi, of Dylan’s “The Man in Me.” But Bourdain wanted the original James Brown track, no matter how much it cost. “I don’t know who’s paying for it,” he said. “But somebody’s fucking paying for it.” He sang the chorus to himself—“I paid the cost to be the boss”—and remarked that one price of leadership, for Obama, had been a severe constraint on the very wanderlust that Bourdain personifies. “Even drinking a beer for him is a big thing,” he marvelled. “He’s got to clear it.” Before he said goodbye to Obama, Bourdain told me, he had underlined this contrast. “I said, ‘Right after this, Mr. President, I’m getting on a scooter and I’m going to disappear into the flow of thousands of people.’ He got this look on his face and said, ‘That must be nice.’ ”

Tom Vitale, the episode’s director, who is in his mid-thirties and has an air of harried intensity, stopped by to check with Bourdain about a shoot that was planned for later that evening. It generally takes Bourdain about a week of frantic work on location to film each episode. He has a small crew—two producers and a few cameramen—who recruit local fixers and grips. His team often shoots between sixty and eighty hours of footage in order to make an hour-long episode. Vitale, like others on the crew, has worked with Bourdain for years. When I asked him what his interactions with the White House had been like, he said, with bewilderment, “I’m shocked we all passed the background check.”

Bourdain was eager to shoot at a bia-hơi joint, a popular Hanoi establishment specializing in chilled draft beer. “We’re hoping for beer?” he asked.

“We’re hoping for beer,” Vitale confirmed. They had already scouted a place. “But, if the energy there is only fifty per cent, maybe not.”

Bourdain agreed. “We don’t want to manufacture a scene,” he said. He makes a fetish of authenticity, and disdains many conventions of food and travel programming. “We don’t do retakes,” he said. “We don’t do ‘hello’ scenes or ‘goodbye, thank you very much’ scenes. I’d rather miss the shot than have a bogus shot.” When he meets someone at a roadside café, he wears a lavalier microphone, which picks up the sort of ambient noise—blaring car horns, shrieking cicadas—that sound designers normally filter out. “We want you to know what a place sounds like, not just what it looks like,” Jared Andrukanis, one of Bourdain’s producers, told me. “The guys who mix the show hate it. They hate it, but I think they love it.”

After filming with President Obama, Bourdain said, “I’m going to disappear into the flow of thousands of people.”

Bourdain is exceptionally close to his crew members, in part because they are steady companions in a life that is otherwise transient. “I change location every two weeks,” he told me. “I’m not a cook, nor am I a journalist. The kind of care and feeding required of friends, I’m frankly incapable of. I’m not there. I’m not going to remember your birthday. I’m not going to be there for the important moments in your life. We are not going to reliably hang out, no matter how I feel about you. For fifteen years, more or less, I’ve been travelling two hundred days a year. I make very good friends a week at a time.”