The most basic, most traditional pesto is this basil-based one that was invented in Genoa, in northern Italy; it’s bright green and wonderfully aromatic. Be sure to add your oil slowly, so that the sauce fully emulsifies – that is, all the ingredients bind together, creating a thick, uniform consistency.

Lots of basil varieties are available, some sweeter, some spicier, and in fact basil is an important ingredient in the cooking of southeast Asia, especially in curries. Each variety will impart its unique flavor to a pesto, so be adventurous, and try whatever type appeals to you. Just remember: you need a lot of it, and it should be fresh and crisp, not wilted or soggy.

Ingredients

• 2 cups fresh basil leaves, (packed)
• 1/4 cup toasted pine nuts
• 1 garlic clove
• 1/2 teaspoon kosher salt, (plus more to taste)
• 1/4 teaspoon ground black pepper, (plus m ore to taste)
• 2/3 cup olive oil
• 1/2 cup grated parmesan cheese

Procedure

1. In a blender or food processor, pulse the basil, pine nuts, garlic, 1/2 teaspoon of salt, and 1/4 teaspoon of pepper until finely chopped.
2. With the blender still running, gradually add enough oil to form a smooth and thick consistency.
3. Transfer the pesto to a medium bowl and stir in the cheese.
4. Season the pesto with more salt and pepper to taste.
5. The pesto can be made 2 days ahead. Cover and refrigerate.