Preparation Method
- Heat a small skillet over medium heat, add the pine nuts, and toast them, shaking the pan often, until they are golden brown and fragrant, 3 to 5 minutes. Transfer the nuts to a plate to cool.
- Place the oil in the blender, followed by the basil, toasted pine nuts, garlic, and salt. Select MANUAL/LO and blend, gradually increasing the speed to SPEED 10 and stopping to scrape down the sides of the blender as needed, until combined. If the outside of the blender jar starts to get warm, add ice water, 1 tablespoon at a time, to the pesto mixture to keep it cool and help it blend.
- Transfer the pesto to a medium bowl and stir in the Parmigiano-Reggiano and butter. Use immediately or store in an airtight container (set a piece of plastic wrap directly on the surface of the pesto to keep it from discoloring) and refrigerate for up to 1 week; or transfer to a resealable plastic freezer bag and freeze for up to 1 month.
Variations
PISTACHIO-MINT PESTO
Substitute pistachios for the pine nuts and substitute fresh mint for the basil.
WALNUT-PECORINO PESTO
Substitute walnuts for the pine nuts. Substitute 11 ⁄2 cups parsley leaves for 11 ⁄2 cups of the basil and substitute Pecorino-Romano for the Parmigiano-Reggiano.
Pro Tip
To keep the pesto from turning brown, blanch the basil leaves before adding them to the blender. Just dunk them in boiling water for no more than a second or two, then plunge into an ice bath to cool.
