There are a lot of options for breakfast and lunch close to the Fieldhouse.

Bruegger's Bagels (includes Jamba Juice & Caribou Coffee) 

https://locations.brueggers.com/us/ia/iowa-city/708-s-riverside-drive  

Village Inn - 

https://www.villageinn.com/locations/iowa-city-ia/

Subway - 

https://order.subway.com/Cart/Menu2.aspx?r=1536714977

Red Pepper Deli & Grill - 

http://redpepperdeliandgrill.com/