Pesto alla genovese is made with Genovese basil, salt, garlic, Ligurian extra virgin olive oil (Taggiasco), European pine nuts (sometimes toasted) and a grated cheese like Parmigiano Reggiano or Grana Padano and pecorino Sardo or pecorino romano.he ancient Romans ate a paste called moretum, which was made by crushing cheese, garlic and herbs together. Basil, the main ingredient of modern pesto, likely originated in India and was first domesticated there. Basil took the firmest root in the regions of Liguria, Italy and Provence, France.