Prepare the ingredients:

Rinse and pat dry the basil leaves. Peel the garlic cloves.

Blend the dry ingredients:

In a food processor or blender, combine the basil leaves, Parmesan cheese, pine nuts, and garlic. Pulse until the mixture is finely chopped.

Add the olive oil:

With the processor running, slowly drizzle in the olive oil. Blend until smooth, scraping down the sides with a spatula as needed.

Season:

Stir in the salt and black pepper. Taste and adjust seasoning as desired.

Store or serve:

Transfer the pesto to an airtight container. If storing, drizzle a thin layer of olive oil on top to prevent browning. Use immediately or refrigerate for up to 1 week.