While Purple Pig will certainly satisfy the "foodie" aspect of your request, it might not fulfill for the hanging out and talking requirement--it's primarily communal seating (although there are some individual tables, they are quite close together) and can get pretty crowded during prime lunch hours. They also don't take reservations so depending on your tolerance for the unknown and likely arrival time, that might be an issue as well.
A few other options that would likely be great, depending on where you want to be:
Terzo Piano in the new wing of the Art Institute
Sable--great food, wonderful cocktails (if your lunch can roll that way)
Balsan--in the Elysian Hotel.
All have threads here I think (not sure about Terzo Piano) and all take reservations.
Good luck and let us know where you end up and how it went!
"Knowledge is knowing a tomato is a fruit; wisdom is not putting it in a fruit salad." Miles Kington