Pie Italian restaurant served up (4)
I believe the answer is:
tart
'pie' is the definition.
(I've seen this before)
'italian restaurant served up' is the wordplay.
'italian restaurant' becomes 'trat' (I've seen this in other clues).
'served up' shows that the letters should be reversed in order.
'trat' reversed gives 'TART'.
(Other definitions for tart that I've seen before include "Tasting sour like a lemon" , "loose woman" , "Acid-tasting; pastry" , "Cutting, pastry" , "The pastry sounds bitter" .)