"Side meat" was mentioned numerous times in John Steinbeck's "The Grapes of Wrath," a story of an Oklahoma family who left home during the Dustbowl years to work in the fruit picking industry in California.
Other person: "Stop stealing bites of side meat and just admit you like steak!"
Ordering chicken wings, for example, from a pizza place, or chicken strips from a sub shop.
Friend #2"Sure, but can we get some side meat with it??"
Friend #1"Ok, sounds like a plan,"