Lunch is on your own. Directly across Campus Dr. from UCI (a 10 minute walk from Engineering) over Watson Bridge is the University Center shopping center with a variety of sit-down and fast food restaurants.
Directions: from the Engineering quad, start at Ring Road and turn right. Walk along Ring Road until you reach the flagpole near Aldrich Hall and Langson Library. Turn right and proceed over the Watson Bridge (follow green path on map) .
More details at: http://drupalcampla.com/information/eatdrink