Created by Tisme on June 17, 2017
Step 1: SEE NOTE BELOW FOR PROCESSOR:
Step 2: Put the basil leaves, pine nuts, garlic and salt in a mortar and pound to a fine puree with a pestle.
Step 3: Stir in the grated cheese and then add the olive oil very gradually, a few drops at a time, beating it with a wooden spoon until you have a green emulsion.
Step 4: Lastly stir in the softened butter.
Step 5: Cook the pasta in a very large saucepan of boiling water (or as directed ~ about 10 minutes) testing frequently, when pasta is just tender, drain and toss quickly in the pesto.
Step 6: Serve with fresh grated parmesan cheese in a separate bowl.