The little bits of fat left in the bottom of the fried fish display counter. Chip shop bosses will often sell you the 'scraps' on a roll or a bap for a very cheap price. Common in north east England, particularly Darlington.
mother: What the hell is this towel doing under Cody's bed and why is it all stuck together? father: Oh God its his goo towel don't touch it. mother: That's so nasty. father: We'll just throw it away.