The French cooks rave about witchetty grubs, say (6)
I believe the answer is:
larvae
'grubs say' is the definition.
(grub is a kind of larva)
'the french cooks rave about' is the wordplay.
'the french' becomes 'la' ('the' in French).
'cooks' indicates an anagram.
'about' means one lot of letters goes inside another.
'rave' is an anagram of 'rvae'.
'la' placed within 'rvae' is 'LARVAE'.
'witchetty' is the link.
I am not very happy about this link. It may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for larvae that I've seen before include "Grubs" , "Wormlike forms of insects" , "Insects in the first stage of life" , "Immature forms of invertebrates" , "Immature forms of insects" .)