In LaGrange, LaGrance Road exit from I-55, I really like:
Bella Bacino's of LaGrange
36 S. La Grange Rd.
La Grange
708-352-8882
for American food with an Italian flavoring. Their grilled calamari is sublime.
Given the timing, though, I would be reluctant to venture too far from the airport, for fear of getting caught in rush-hour traffic while you're trying to make a flight. Instead, I would grab some double-crust "stuffed" pizza at Giordano's at the airport, so you don't have to worry about making a flight. You can order the pizza ahead so you don't have to wait 30-45 minutes for it to bake. Giordano's is located at 63rd and Cicero, at the southwest corner of the airport and just a half mile south of the terminal building.
Giordano's
6314 S. Cicero
(773) 585-6100