The taste you get in your mouth of your last meal promptly after you burp. Usually occurs after consuming something along the lines of hot wings or spaghetti.
I had terrible Deja Food after I tore up a couple dozen wings and kept choking on the taste of them for hours after when i'd burp.
The distinct feeling of seeing food you have engulfed before.
Brian: Wait a minute, i've seen this meatball before!
Chris: Seems like a typical Deja food.