Below are 3 recommended lunch places close to IIT Mies Campus (around 10 minute walk from the confernce venue). There are also several smaller places, at the southern boundary of campus, where you can grab a sandwich or salad - you can find those on google maps.
Stix n Brix (https://stixnbrix33.com/). This is a simple, but good-quality, place serving thin-crust pizza, sandwiches and salads. Open for lunch every day except Monday.
Franco's (https://www.francoschicago.com/). This is an American-Italian restaurant. Open for lunch Monday-Friday.
New Furama (https://www.newfuramasouth.com/). This is a Chinese restaurant, known for its dim-sum. Open for lunch every day.