One week, 32 countries, and an eyeball taco later, Susan Hack discovers that Chicago—not New York or L.A.—is the real culinary crossroads of the world

At Tito's Tacos, a food stall in a gritty industrial zone next to the south branch of the Chicago River, a caballero in a white Stetson is ladling pieces of steamed cow's brains onto fresh-grilled tortillas. Despite lacking a press agent, a restaurant consultant, a TV show, a spin-off bistro, or even a proper building and regular hours (it's open only on Sundays), Tito's has managed to develop a cult following on dozens of Web message boards dedicated to celebrating America's ethnic food. Its house specialty is the $1.25 taco de ojo, the eyeball taco.

I'm not a professional gourmet or even an especially inventive cook, but two decades of journalistic life overseas (I live in Cairo now) have presented plenty of opportunities to conquer my gag reflex and broaden my palate. In South Africa I ordered—and enjoyed—mopane worms stewed in tomatoes (they look like white asparagus tips and taste like artichoke hearts). While in a Hanoi produce market, I resisted the temptation to barf while sampling a morsel of barbecued dog (think a combination of Peking duck and roast suckling pig).

Then again, I've always had an adventurous palate. As a kid growing up in Chicago in the 1960s and '70s, I once accepted my best friend's dare to try a spoonful of canned cat food (it brought to mind ham mixed with sawdust). In addition to a cast-iron stomach, I also had a big appetite, along with the eclectic eating habits of a Jewish-Lithuanian/Christian-Filipino household. The American-born children of immigrants, my parents belong to a generation that was encouraged to assimilate. Yet gefilte fish and pork adobo both appeared on our table (along with TV dinners), and I was raised to believe that no food was out of bounds. The Chicago of my childhood was hardly a culinary beacon (the city's most famous celebrity chef, Charlie Trotter, opened his eponymous restaurant in 1987), but it had its own specialties: Polish sausages from the pushcarts in Grant Park; whitefish from Lake Michigan, smoked or boiled Norwegian-style; and buckets of spring-running smelt caught, fried, and eaten by the lakeshore. Compared with New York and Los Angeles, Chicago had (and still unjustly suffers from) a reputation for Midwestern provincialism. But no matter: The nation's original multicultural city has always produced fresh generations of ethnic cooks and enthusiastic eaters.

So I'm taken aback when, in my own hometown, I end up meeting my Waterloo: Tito's ojo taco platter. The garnish of grilled onions, green chilies, and stringy shreds of brain looks appetizing, but the jawbreaker-sized mammalian orb, enveloped in gelatinous white tissue, turns out to be more than I can chew.

I change my mind and order something I think I'll actually like, a carne asada taco filled with grilled skirt steak and followed, on this crisp October day, with a champurado, that delicious Mexican hot chocolate spiced with cinnamon, almonds, vanilla, and brown sugar, and thickened to a near pudding with cornmeal. People of Hispanic origin now make up 27 percent of Chicago's population of 2.9 million, which means that the New Maxwell Street Market, southeast of the Loop and originally a bazaar for nineteenth-century stockyard workers, is evolving again. A former stronghold of Eastern European immigrants, it became a popular shopping destination for African Americans in the early twentieth century. Today, it resembles a Mexican carnival, one whose street stalls offer a south-of-the-border smorgasbord: goat soup and barbecued goat, Oaxacan tamales wrapped in corn husks and banana leaves, and churros filled with goat milk caramel. Around me, women pick over tomatillos, cactus paddles, and a rainbow of aromatic chilies at produce stands, while men bargain for tools and car parts and kids browse tables laden with plastic toys, hard candy, and pirated CDs.