Pesto alla Genovese

Cook's notes

Traditionally pounded — the name comes from pestare, to pound, and a mortar and pestle give the silkiest result. The food processor is the quick, low-spoons route; just pulse, don't purée.

Bright green = done right. Heat and over-blitzing oxidize the basil dark and bitter, so chill the bowl/blade if you can and move fast.

Never heat pesto — toss it into hot pasta off the stove, with a little starchy pasta water to make it cling.

Store airtight with a film of olive oil over the surface (3–4 days), or freeze in an ice-cube tray for single portions.

About the pecorino: the traditional Genovese cheese is Sardinian pecorino (Fiore Sardo / Pecorino Sardo) — a mild, slightly sweet, nutty sheep's-milk cheese that blends into the basil without overpowering it. It's notoriously hard to find in the U.S., so this calls for the widely available Pecorino Romano instead. Romano is sharper and much saltier, so use a slightly lighter hand and go easy on the added salt. If you can get Sardinian pecorino, use it — it's the better cheese here. In the U.S. it's mostly an online buy; look for Pecorino Sardo Dolce (the young, mild style — the best match for pesto), such as from Olio & Olive. It sells out often — if it's out of stock, enter your email on the product page to be notified when it's back.

Provenance: adapted from the classic Genovese recipe — the traditional Ligurian proportions.

Best with fresh pasta: toss it into homemade pasta off the heat, with a little starchy pasta water to help it cling.