Trattoria plateful (5)
I believe the answer is:
pasta
'trattoria plateful' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for pasta that I've seen before include "Italian cooking staple" , "Staple food of Italian origin" , "Spaghetti, perhaps" , "eg Tortellini" , "E.g. fusilli" .)