Chicago's reputation as one of America's finest food cities is thoroughly deserved. It is, after all, home to chef Grant Achatz's celebrated Alinea and some 25 other Michelin-starred places. The thing is, when you read 'Chicago', you didn't think 'Grant Achatz's parmesan balloons', did you? No. You, like the rest of the world – including Achatz, probably – thought hot dogs and deep-dish pizza.