Vincent's completely undeserved smugness is interrupted. He frowns with a potato wedge still sticking out of his mouth.

"Nah, I just know potatoes," he begins to argue, pulling the rest of the fry into his mouth before saying the next logical thing, "They grow under dirt. An' I grew under dirt. Potato expert."

He gestures between himself and... Probably the fries. Is he trying to say he's got some kind of special connection to spud-based foods because of his growing up in an underground society? Yes. And it's dumb, he knows it's stupid, but he's intentionally trying to be absurd in the hopes of getting a chuckle out of all this.

"Once you start addin' stuff that ain't potato it ain't a potato wedge no more."