Asking the question of whether or not one would. Usually referring to someone on television or on the street but can be used in any situation.
Note: Any negative answer can be immediately met with the response "On a plate?".
(Carol Vorderman appears on a television commercial)
"Bleugh! No! You SICK!"
"Yeah, yeah, you're right... On a plate though?"
"Hmm... yeah, I spose actually"