Step 1

In the bowl of a food processor, combine the basil (blanched, if desired; see NOTE), olive oil, pine nuts, garlic and salt. Process until smooth, 30 seconds to 1 minute, stopping to scrape down the bowl, if necessary.

Step 2

Transfer the basil puree to a medium bowl and stir in the cheese and softened butter, if using. Taste, and add additional salt if desired. Serve or refrigerate until needed.

Step 3

NOTE: To make pesto that will stay green for up to a week, blanch the basil: Fill a medium bowl with ice water. Bring a quart of water and 2 teaspoons of fine sea or table salt to a rolling boil over high heat. Gently stir in the basil, and cook for 45 seconds; it will become deep green and wilted. Using a slotted spoon, transfer the basil to the ice bath. Once it’s cold, strain and use your hands to squeeze out any excess water before proceeding with the recipe.