Criticise cook (5)
I believe the answer is:
roast
This clue is a double definition.
'criticise' is the first definition.
(I've seen this in another clue)
'cook' is the second definition.
(I know that cook is a is a more specific form of the action of roast)
(Other definitions for roast that I've seen before include "Cooked meat; criticise" , "Cooked joint" , "One way to cook meat" , "Criticise severely" , "Traditional Sunday lunch" .)