Combine parsley, basil, walnuts, paresan and garlic in a food processor. Process until mixture is finely chopped. Add chicken broth and puree. With machine running, gradually add olive oil and process until mixture is smooth. Transfer to a large bowl. Season with salt and pepper. Makes enough for 1 pound (dry weight) of pasta. Top with e few toasted nuts. (Mixture can be made about two hours in advance).