Step 1: Lightly toast the pine nuts in a dry skillet over medium-low heat for 3-5 minutes, shaking frequently, until fragrant and lightly golden. Be careful not to burn them. Let cool completely.
Step 2: In a food processor, combine the fresh basil leaves, toasted pine nuts, grated Parmigiano-Reggiano cheese, and peeled garlic cloves. Pulse several times until the mixture is coarsely chopped. Scrape down the sides of the bowl with a spatula.
Step 3: Add the salt and black pepper. With the food processor running on low speed, slowly drizzle in the extra virgin olive oil through the feed tube. Continue to process until the mixture is well combined and forms a thick, somewhat chunky paste. Avoid over-processing, as this can generate heat and bruise the basil, making the pesto dark.
Step 4: Taste the pesto and adjust seasoning (salt, pepper, or even a squeeze of lemon juice) as needed. If it's too thick, add another tablespoon or two of olive oil. The ideal basil pesto recipe should be spreadable but not watery.
Step 5: Transfer the fresh basil pesto to an airtight container. To prevent oxidation and keep its vibrant green color, pour a thin layer of olive oil over the surface of the pesto before sealing and refrigerating. Your homemade basil pesto recipe is now ready to use or store!