Appetiser covered by lime zest (4)
I believe the answer is:
meze
'appetiser' is the definition.
(Middle Eastern appetiser)
'covered by lime zest' is the wordplay.
'covered by' indicates a hidden word.
'MEZE' can be found hidden inside 'lime zest'.
(Other definitions for meze that I've seen before include "Mediterranean snacks" , "Greek or Turkish starter selection" , "Mediterranean dishes" , "Turkish hors d'oeuvres" , "Small dishes served together in Turkish and Greek cuisine" .)