THE EXOTIC LUMP OF FLESH currently before Tony has been extracted from behind the gills of a yellowtail. This savory portion—called the "collar"—would be trashed at most American restaurants, but here at Sake Bar Hagi, the Japanese den in Midtown Manhattan that Tony and I have squeezed into this August evening, it's a delicacy. In the spirit of culinary adventure, Tony brought me through a barely marked door, down a flight of stairs, and into this retreat of Japanese businessmen to sample a variety of challenging entrées. He is 51 years old and six foot five, a stork-like creature with salt-and-pepper hair and an ability to remain unnervingly lucid in almost any situation, like when he'll later go Colonel Kurtz on me and confess that No Reservations has so tweaked his outlook that he's ready to abandon America altogether.

Right now, though, he is craning his neck to catch a glimpse of the chef. "I still see the world from his perspective, the guy who's standing back there through that window," he says.

This is a fair distillation of Tony's method of world exploration. In a rebuke to the lightweight hosts who populate travel and food TV, Tony has developed a more vigorous approach, one that dares you to stick with him for an hour as he learns about a people by eating and drinking what they do. No Reservations might be best summarized as Paul Theroux with more cigarettes. There is no set format, just a location—frequently exotic (Namibia, Uzbekistan, Polynesia), sometimes not (New Jersey, Ohio, South Carolina)—and Tony's intrepid stomach. Mostly avoiding four-star restaurants, he turns up at market stalls, family weddings, and more primitive food stations to sample whatever's being served. Each episode plays out like a digressive, impressionistic essay that can veer off in all manner of unusual directions. At times, Tony will be deliriously happy, as when munching on puffin meat in Iceland; at others, he can be inconsolably morose, as when receiving a full-body massage from a sparsely clothed Uzbek man, an experience he called "sexual humiliation." The show draws the highest ratings on the Travel Channel, perhaps because it retains the giddy flavor of real traveling and eating. Thanks to heavy doses of alcohol and profanity, it's also the only show on the network preceded by a parental warning.

"I have the luxury of being honest," Tony says, holding a piece of yellowtail between his chopsticks. "I don't know many travel- or food-show hosts that could say that something sucks, that they never want to come back."

Or, for that matter, decide to say nothing. During an episode in Belfast that aired in January, Tony had prepared for a standup in front of one of the city's "peace walls," which for years separated warring Catholics and Protestants. But when the tape started rolling, he looked uncertainly at the camera for a moment and said, "Anything I say on the subject is going to sound uninformed and idiotic." Then he walked away.