My wife and I will be visiting Chicago for a couple days later this month. We have a nice dinner planned at North Pond, but are looking for ideas for some less expensive food adventures that will give us a real sense of Chicago and will be different from what we're going to find at home in Boston. We're fairly adventurous, ethnic is fine, off the beaten path is okay too. We'll be staying in the River North area and traveling by cab/public transportation. Ideas?