Interrogate part of the cooker (5)
I believe the answer is:
grill
I believe this is a double definition.
'interrogate' is the first definition.
(I've seen this in other clues)
'the cooker' is the second definition.
(device for grilling food)
'part of' is the link.
(Other definitions for grill that I've seen before include "keep on with questions?" , "Framework of metal bars" , "Question closely" , "Broil" , "Question; cook" .)