Ingredients for 600 gr (21.16 oz) of pasta
50 gr (1.76 oz) Fresh Basil leaves
6 Tablespoons Grated Parmesan Cheese PDO (parmigiano Reggiano) or Grana Padano Cheese PDO
2 Tablespoons Grated Pecorino cheese PDO
2 Garlic Cloves, peeled
1 Tablespoon Pine Nuts
Sea Salt, some grains
½ Glass Extra Virgin Olive Oil
The original genoese pesto is made in a marble mortar with a wooden pestle, not in a blender; basil leaves and extra virgin olive oil should be made in Liguria under PDO certification mark (Protected Destination of Origin). If you use a different variety of basil avoid the one with a mint taste. The garlic should be from Vassalico (Imperia), if you use another type of garlic make sure is no pre-peeled or fermented. The preparation of pesto has to be done at room temperature and as quickly as possible to prevent oxidation.
Gently wash the basil leaves in cold water and dry them on a kitchen towel (don't rub). Place the garlic cloves in the mortar and start pounding. Add a few grains of salt and pound some more. After you're done, add the basil leaves a few at a time. Using the pestle with a light rotary movement, grind ingredients against the wall of the mortar until ground to a paste. The essential oils of basil are found in the little veins of the leaves, and to get the best from them you have to pound gently rotating the pestle, not by squishing the leaves. When the basil will start to drip a bright green liquid it's time to add the pine nuts and keep pounding then add grated pecorino, grated parmesan and stir with a wooden spoon to combine.
When the ingredients are well combined, turn out into a large bowl, slowly pour in the olive oil until you obtain a very fine and smooth pesto that should not be greasy, the amount of oil used must be well absorbed and not floating on top. This sauce is perfect for dressing up any types of pasta, the traditional pasta from Liguria are: trofie, trofiette and trenette