Homemade Pesto Recipe

Place the walnuts and garlic in the bowl of a food processor fitted with a steel blade. Process until coarsely chopped, about 10 seconds. Add the basil leaves, salt, and pepper and process until mixture resembles a paste, about 1 minute. With the processor running, slowly pour the olive oil through the feed tube and process until the pesto is thoroughly blended. Add the Parmesan and process a minute more. Use pesto immediately or store in a tightly sealed jar or air-tight plastic container, covered with a thin layer of olive oil (this seals out the air and prevents the pesto from oxidizing, which would turn it an unappetizing brown color). It will keep in the refrigerator for about a week.