Dining out is one of our purer expressions of desire: the transformation of mere sustenance into something worth paying for and obsessing over. Which is why I've always thought that restaurants can reveal, in a more visceral way than books or movies or even Lady Gaga, what we crave as a culture.

I recalled this theory recently during a disorienting lunch at Street in L.A. Like a growing number of restaurants nationwide, Street turns the tables on last year's fancy-food-truck trend by rounding up humble treats from Beijing's hutongs and Mexico City's callejones, and repositioning them in a gourmet restaurant, complete with silverware and toilets. It's street snacking as a fine-dining concept.

At Street, your receipt reads like a travelogue. After touching down in Mumbai (paani puri), Singapore (Kaya toast), Kuala Lumpur (black-pepper clams), and Kiev (varenyky dumplings), I returned to Los Angeles (Kobe beef chili dogs) with the gastrointestinal equivalent of jet lag. The globe-trotting menu at G Street Food in Washington, D.C., is nearly as encyclopedic. Chicago's Wave hosts a rotating selection of international food carts every Wednesday. Pedigreed eateries specializing in the street snacks of Mexico City have earned raves in Philadelphia (Distrito), Chicago (Xoco), and New York (La Superior, La Lucha, Cascabel). There are artisanal hot dogs in Brooklyn (Bark), lavish Cambodian sandwiches on the Lower East Side (The Norry), and highfalutin French-Vietnamese noodles at the new Momofuku spot, Má Pêche, inside Manhattan's ritzy Chambers Hotel, which is about as far from eating on the street as you can get.

Some of what this fad says about our society is flattering. For decades, restaurants have responded to recessions by offering their customers gussied-up versions of comfort food, like $19 burgers. But street food challenges rather than comforts American palates, and its rise vindicates the culinary values of authenticity and adventurousness—both among chefs, who are now feted for cooking the weird stuff they've always loved to eat, and among diners, who, after watching guys like Anthony Bourdain scarf down sup tulang on TV, have finally summoned the cojones to try some themselves.

But the trend also hints at something distressing about our mindset. A few days before visiting Street, I led a group of friends to a food truck called Antojitos de la Abuelita, where we dined under a red curbside tent on huitlacoche and caldo de gallina while the owners helped us suss out what exactly we were eating. For adherents, the experience of eating on the street—often in an unfamiliar part of town, or the world, where interacting with the cook and community is unavoidable—is as much a part of the street-food recipe as tortillas and tongue meat. It's not just that noshing at places like Antojitos de la Abuelita will always make more economic sense than spending twice as much at Street, and that, in a recession, real street vendors arguably need our money more than the restaurateurs who repurpose their recipes. It's that a simulation isn't sufficient. The deeper hunger that's driving the street-food trend—the desire to reach out and connect with a globalized world that we're more aware of and reliant on than ever—is worth celebrating. But ultimately, that kind of craving will be satisfied only if places like Street inspire us to undertake the tricky work of actually engaging with other cultures—and not if they serve merely as safe, trendy substitutes for the real thing.