3/4 cup pine nuts or coarsely chopped macadamia nuts (6 ounces)
5 cups basil leaves, chilled and perfectly dry
6 small garlic cloves, quartered
1/3 cup freshly grated Parmesan cheese
3/4 cup extra-virgin olive oil, plus more for sealing
Kosher salt and freshly ground pepper
Preheat the oven to 400°. Toast the nuts on a baking sheet for about 4 minutes, or until lightly browned.
Coarsely chop the basil leaves. In a large mortar, combine the basil and garlic and pound to a coarse paste. Add the nuts and pound until a smooth paste forms. Stir in the Parmesan, then 3/4 cup of the olive oil. Transfer the pesto to a bowl and season with salt and pepper. Smooth the surface and pour a little olive oil on top to seal.