Cook to carve ham (7)
I believe the answer is:
overact
'ham' is the definition.
(ham can mean to overact)
'cook to carve' is the wordplay.
'cook' indicates anagramming the letters.
'to'+'carve'='tocarve'
'tocarve' anagrammed gives 'OVERACT'.
(Other definitions for overact that I've seen before include "behave exaggeratedly" , "Exaggerate" , "Perform hammily" , "Be unsubtle on stage" , "Play (part) in an exaggerated manner" .)