Will be in chicago in two weeks to celebrate my brother's 40th birthday. I'm a chicagoan born and bred, but have spent the last eight years in new york city. In that time, I've (shamefully) refocused my food obsessions onto the east coast. So, we will be a group of 6-8 adventurous eaters, ethnic is fine, as well as upscale. Whatever persuasion/typology, the food has to be authentic and the setting upbeat, maybe even swanky. And there has to be hope of getting a reservation within the two week margin. Thanks in advance for any thoughts, suggestions.