Cook needs the last of cheese grating (6)
I believe the answer is:
grille
'grating' is the definition.
(grille is a kind of grating)
'cook needs the last of cheese' is the wordplay.
'cook' becomes 'grill' (grilling is a form of cooking).
'needs' means one lot of letters go next to another.
'the last of' indicates one should take the final letters.
The final letter of 'cheese' is 'e'.
'grill'+'e'='GRILLE'
(Other definitions for grille that I've seen before include "Protective metal framework" , "Frame of bars" , "Part of an air-cooling system" , "It affords ventilation" , "A metal grating in door or window" .)