When you are in a foreign country and you realise that the food you ordered isn't what you expected it would be. Instead, the look, smell, taste and/or texture is somehow unnerving, unrecognisable and disappointing and you can't bear eating it.
Paul: Oh! I'm so hungry! Where's my chicken?
(Waiter brings food to the table)
Paul: What IS that!? I thought it was going to be stir-fried chicken but it's actually chicken tendons and cartilage!
Nat: Oh Paul, that is food disillusion right there. Do you want some of my fries?