A sign that's similar to the touch or spud sign, but uses the "rock on" sign rather than a fist to touch. This is a common form of showing respect to a chunk, a mixture of chav and punk.
Immz: Dat outfit iz unique bruv.
Immz: Iz you a chunk?
Immz: Chunk touch! Oh yeeeeeeah!
Immz: Those sunglasses are CHUNK bruv.
Ela: I'm not chunk.
Immz: Whatever, chunk touch! Oh yeeeeeah!