After years running one of the city's most upscale dining rooms, Metropolis American Grill, restaurateur David Rabinovitz decided he wanted to try something completely different. So he started grilling hot dogs. And, despite his association with more sophisticated cuisine, he discovered that even the biggest food snobs will confess to an illicit craving for a thick, juicy wiener tucked into a firm bun. That's why Rabinovitz opened Relish five months ago, serving grilled-to-order, 100 percent all-beef dogs with various toppings -- including the best-selling Chicago Classic (smothered with mustard, relish, chopped onion, pickles, peppers and celery salt). Making a meal out of a hot dog isn't just economical, Rabinovitz discovered, but potentially therapeutic -- it's a dish indelibly associated with happy childhood memories, such as picnics and ballgames. His success proves that he wasn't alone in his passion. "I knew I'd get a lot of students and working-class customers," he says, "but I get lots of society people and white-collar professionals, too." Who knew?