Classic Basil Pesto

1/2 cup basil leaves
4 large or 6 medium garlic cloves
1/3 cup shredded Parmesan cheese
3 tablespoons walnuts 
2 tablespoons minced parsley
1/2 teaspoon salt
1/4 cup extra-virgin olive oil

1. Put basil in a mortar with garlic, Parmesan cheese, walnuts, parsley, and salt. Pound until smooth, then add olive oil and mix until smooth. Or, whirl all ingredients in a food processor.