Pasta sauce (9)
'pasta sauce' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for pesto that I've seen before include "Pasta sauce based on basil" , "A sauce served with pasta" , "Sauce of basil, pine nuts, etc" , "Sauce of basil, pine nuts and garlic" , "Saucy work" .)
'pasta sauce' is the definition.
(I know that carbonara is a type of pasta sauce)
This is all the clue.
(Another definition for carbonara that I've seen is " Type of pasta sauce".)