Sauce with basil and pine nuts (5)
I believe the answer is:
pesto
'sauce with basil and pine nuts' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for pesto that I've seen before include "Basic sauce" , "Sauce made of basil and cheese" , "Saucy work" , "Ligurian food" , "Sauce of basil, pine nuts, etc" .)