Carves piece of sweet chestnut (6)
I believe the answer is:
Here is my best explanation:
'carves' is the definition.
'of sweet chestnut' is the subsidiary indication.
'of' indicates the answer is hidden within the clue.
'etches' is hidden within 'sweet chestnut'.
'piece' is the link.
(Other definitions for etches that I've seen before include "Impresses deeply as into metal plate" and "Engraves".)