The origins of this sauce are very ancient ones: the first recipe of the Genoese pesto to have been written down dates back to the mid-19th century.
There are seven basic ingredients that give life to this sauce: Genoese basil, extra-virgin olive oil, coming from the Ligurian Riviera, Parmigiano Reggiano (or Grana Padano alternatively), Sardinian Pecorino, pine nuts, garlic, salt. The true Geonese pesto is prepared with a marble mortar and a wooden pestle.
If you want to prepare it at home, here is the original recipe of the Genoese pesto.
First, you need to wash the basil with cold water. Pound the garlic in the mortar with some grains of coarse salt. When garlic and salt have reached a creamy texture, add a handful of pine nuts. At his point, incorporate basil leaves and pound this mixture with a circular and long movement in the mortar. Lastly, add the cheeses and the extra virgin olive oil, poured gently. At this point the pesto is ready to be served, possibly as a sauce for trofie or trenette (types of pasta).