Uncovered starter of unsalted head of langoustine in endive salad (8)
I believe the answer is:
unveiled
'uncovered' is the definition.
(unveiling is a kind of uncovering)
'starter of unsalted head of langoustine in endive salad' is the wordplay.
'starter of' says to take the initial letters.
'head of' suggests taking the first letters.
'in' is an insertion indicator.
'salad' is an anagram indicator (salad can refer to a mixture).
The initial letter of 'unsalted' is 'u'.
The first letter of 'langoustine' is 'l'.
'endive' is an anagram of 'nveied'.
'l' put within 'nveied' is 'nveiled'.
'u'+'nveiled'='UNVEILED'
(Other definitions for unveiled that I've seen before include "Removed concealing drapery from as in ceremony" , "Revealed, uncovered" , "Shown for the first time" , "Took cover off - revealed" .)