Basil Pesto can be just as successful made without nuts as with pine nuts or walnuts. Garlic is optional too. This recipe emphasizes fresh basil and good quality extra virgin olive oil and parmesan cheese.
Wash the basil and pat dry with a kitchen towel. Using a large kitchen knife, mince the basil. Grate the parmesan cheese on the smallest grate on a cheese grater.
Combine the basil and parmesan cheese in a medium sized bowl. Add the garlic and pine nuts if using. Add 1 cup of extra virgin olive oil and mix to combine. Continue adding extra virgin olive oil until you have the desired consistency, up to ½ cup more. Add salt to taste about 5-10 cranks of a salt grinder.
Alternatively you can add the basil to a food processor or blender along with an ice cube (to prevent the blades from burning the basil leaves), then add the cheese and the olive oil slowly - start with 1 cup, then add additional olive oil to get your desired consistency. Add salt to taste about 5-10 cranks of a salt grinder.
Finally, if not using immediately, top the bowl with a lick of olive oil. This will prevent the basil from being exposed to the air and oxidizing.