For the pesto: Pulse almonds in a food processor until smooth. Add parsley, chives, oil and Parmesan; process until smooth. Season pesto with salt and pepper to taste.

Bring a large pot of generously salted water to a boil (4-6 quarts). (Rule of thumb for pasta water or water used for blanching vegetables: 1 heaping tablespoon per quart of water.) Add pasta, stirring occasionally, until slightly undercooked, or “al dente.” Reserve two cups of the pasta water, then drain the pasta.

toss pasta and pesto in a large bowl, adding pasta cooking liquid by the 1/4 cup until it reaches a desired “saucy” consistency. Season with salt and pepper and additional parmesan, if desired.

Do Ahead: pesto can be make 5 ays ahead and stored in a tightly sealed container. For best results and to retain color, place plastic wrap directly on the surface of the pesto, even is storing in a lidded container. It’s the exposure to oxygen that will turn it brown.