Severely criticise cook (5)
I believe the answer is:
roast
This clue is a double definition.
'severely criticise' is the first definition.
(I've seen this before)
'cook' is the second definition.
(I know that roast is a more specific form of cook)
(Other definitions for roast that I've seen before include "Cook with dry heat" , "Sunday dinner" , "Grill" , "Cook (meat) in oven" , "Meat to get hot" .)