Step 1: Prepare the Basil: Gently wash and thoroughly dry the basil leaves. Removing excess moisture prevents the pesto from becoming diluted.
Step 2: Combine Ingredients: In a food processor, combine the basil leaves, garlic, Parmesan cheese, and optional walnuts or sunflower seeds.
Step 3: Process to a Paste: Pulse the ingredients until a coarse paste forms. Avoid over-processing, which can heat the basil and darken its color.
Step 4: Add Olive Oil: With the food processor running, slowly drizzle in the extra virgin olive oil until the pesto reaches a smooth, emulsified consistency.
Step 5: Season to Taste: Add lemon juice (if using), salt, and freshly ground black pepper to taste. Pulse briefly to incorporate the seasonings.
Step 6: Adjust Consistency: If the pesto is too thick, add a tablespoon or two more of olive oil or a splash of water to reach the desired consistency.
Step 7: Serve or Store: Serve immediately over pasta, sandwiches, or as a spread. To store, transfer the pesto to an airtight container, drizzle a thin layer of olive oil over the top to prevent oxidation, and refrigerate for up to 5 days.
Optional tips: For a creamier pesto, add a tablespoon of ricotta cheese. Toasting the walnuts or sunflower seeds before blending enhances their flavor. If basil isnt available, try using spinach or arugula for a different flavor profile.