Prepare Basil: Wash the fresh basil leaves thoroughly under cold water and pat them dry with a paper towel. Remove any tough stems.

Toast Pine Nuts: In a dry skillet, toast the pine nuts over medium heat for 2-3 minutes until they turn lightly golden. Stir frequently to prevent burning. Remove from heat and let them cool.

Combine Ingredients: In a food processor or blender, add the basil leaves, grated Parmesan cheese, toasted pine nuts, and peeled garlic cloves.

Pulse: Pulse the ingredients a few times until they are roughly chopped and well combined.

Stream in Olive Oil: With the food processor or blender running, slowly stream in the extra-virgin olive oil until the mixture becomes smooth and creamy. You may need to stop and scrape down the sides of the bowl with a rubber spatula to ensure all the ingredients are incorporated.

Season: Add salt and pepper to taste. Pulse briefly to mix them in.

Taste and Adjust: Taste the pesto sauce and adjust the seasoning or consistency if needed. You can add more olive oil for a thinner sauce or more Parmesan for a thicker texture.

Serve or Store: Use the pesto sauce immediately as a pasta sauce, spread, or dip. To store, transfer it to an airtight container and cover the surface with a thin layer of olive oil to prevent oxidation. Store in the refrigerator for up to one week.