Originally Posted by
tsg20
I'm going to have 3 hours to kill at ORD tomorrow (my wife gets in on a later flight). Flying LHR-ORD on UA, presumably I get into T5 - is there any way to get to Tortas Frontera, or would that involve leaving security? I'm guessing so, but...
Are you connecting to a domestic flight or is Chicago your final destination?
In order to kill 3 hrs, you can start out with a relaxed walk to the immigrattion and customs and not joining the mad dash. The immigration and customs process funnels everyone outside security (landside). Now,
unless you are connecting to a domestic flight or you buy a refundable ticket, there is no way to get inside security (airside) in other terminals, where the Tortas Frontera are. 
At T5, the lower (arrivals) floor has more comfortable chairs to sit on, but only McDonalds for food. There are monitors where you can track the ETA for your wife's flight (assuming she too is coming into T5).
The upper (departures) floor has more interesting food options in a food court, and also a bookstore/newsstand.
Divide your time between the two.