Marinara or pesto (5)
I believe the answer is:
sauce
'marinara or pesto' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for sauce that I've seen before include "Flavoursome relish or dressing" , "Cheek; condiment" , "Lip; foodstuff" , "Dressing served with food" , "Informal impudence or food flavouring" .)