Use a cleaver repeatedly and promptly (4,4)
I believe the answer is:
chop chop
'promptly' is the definition.
(I've seen this before)
'use a cleaver repeatedly' is the wordplay.
'use a cleaver' becomes 'chop' (I've seen this before).
'repeatedly' indicates the doubling of some letters.
'chop' doubled is 'CHOP-CHOP'.
'and' acts as a link.
(Other definitions for chop chop that I've seen before include "Fast" , "Get a move on" , "Promptly!" , "Hurry up!" , "Quick" .)