In this classic version of pesto, the basil leaves are blanched in boiling water, then quickly shocked in ice water, to give the sauce a brilliant green hue and to reduce any bitterness.
When basil is in season, I can't make enough pesto. The classic Italian sauce native to Genoa tastes delicious on everything from pasta to pizza to grilled fish. It's excellent stirred into salads or slathered on sandwich bread. Although store-made pesto