Starters of niçoises: endives cored, stale, curl up (6)
I believe the answer is:
nestle
'curl up' is the definition.
(I've seen this in another clue)
'starters of nicoises endives cored stale' is the wordplay.
'starters of' indicates taking the first letters.
'cored' says to hollow out the word (remove centre letters) (the word has its insides or core removed).
'stale' with its centre removed is 'stle'.
The initial letters of 'nicoises endives' is 'ne'.
'ne'+'stle'='NESTLE'
(Other definitions for nestle that I've seen before include "lie comfortably" , "Swiss food and drink company" , "Snuggle into, say, embrace" , "Settle cosily" , "Lie snugly (in a place)" .)