Basil-based pasta topping (5)

I believe the answer is:

pesto

(Other definitions for pesto that I've seen before include "Pasta sauce variety" , "Basil-based sauce" , "Ligurian food" , "Pasta sauce mainly of basil and cheese" , "Sauce of basil, pine nuts and garlic" .)

I've seen this clue in the King Feature Syndicate.

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