Clarified butter (4)
I believe the answer is:
ghee
'clarified butter' is the definition.
(ghee is a kind of clarified butter)
This is the entire clue.
(Other definitions for ghee that I've seen before include "Indian form of butter" , "Clarified butter used in Indian cookery" , "Clarified butter used in Indian cooking" , "Use it to cook" , "clarified product" .)