Question for cook (5)
I believe the answer is:
grill
I believe this clue is a double definition.
'question' is the first definition.
(to grill is to interrogate)
'cook' is the second definition.
(grilling is a form of cooking)
'for' is the link.
(Other definitions for grill that I've seen before include "Grating" , "interrogation?" , "what restaurant has to offer?" , "Cook under direct heat" , "Question aggressively" .)