Public Domain Meal
Making your entire lunch out of items other people at your workplace have discarded or explicitly said, "I'm not going to eat this. Does anyone want it?" An example could be a sandwich made from leftover bread and old cream cheese from that time two months ago when someone brought bagels in for everybody.
Jason forgot his wallet at home, so he didn't get his usual Chipotle lunch and instead ate Lindsay's leftover fried rice with leftover pizza as a public domain meal.