Cheese used in apricot tart (7)
I believe the answer is:
ricotta
'cheese' is the definition.
(ricotta is a type of cheese)
'in apricot tart' is the wordplay.
'in' indicates a hidden word.
'RICOTTA' is hidden within 'apricot tart'.
'used' is the link.
(Other definitions for ricotta that I've seen before include "one brought on board?" , "Italian 8 across" , "may come from Italian press?" , "Ital. cheese" , "may be served with biscuits" .)