Cheese left, acknowledge unfinished (4,5)
I believe the answer is:
port salut
'cheese' is the definition.
(I've seen this before)
'left acknowledge unfinished' is the wordplay.
I cannot really see how this works, but
'left' could be 'al' (I've seen this in other clues) and 'al' is located in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for port salut that I've seen before include "Type of French cheese" , "mild cheese" .)