Eating a Ditka is a term used to tell someone to Shut the Hell up, or more universally to Get On Your Level (GOML). Also used when one-upping someone in competition. The term carries weight for two reasons. 1.) The resemblance to the word Dick, and 2.) How intense Mike Ditka is in real life.
dad: because it's fun, James. And, please, because I am in a bad mood since yesterday, having gotten a parking ticket, please eat your brocoli. just pick your things so I can take you to your class.