I wouldn't try to leave the airport, you won't have enough time to get out, get lunch, and get back. Traffic around there is totally un[predictable, you may be leaving plenty of time to get back,a nd end stuck in a cab for 25 minutes a few blocks from the airport. There are a couple of hotels very close by if you really need to get out, the Marriott for example has shuttle busses, don't have a clue how their food offerings are.

I agree with the food court idea, it's landside, so you can grab lunch there at one of the different restaurants, I believe the pizza place even has table service. The gate entrance is at the top of the stairs, and every now and then you can take a peek and see what's going on and if the lines are long say bye and run for the gate.