I found this "restaurant" quite by accident while heading toward Midway Airport. A favorite with locals, Bobak's is known for their Polish sausage - and everything they say is true. I had a sausage in a roll, with all the fixings, for $1. That's a complete meal in iself.
If you're in the area, this is definitely a place to stop. I brought home some grill-r and liver sausage from the incorporated grocery store to enjoy later this week.