First clean the basil leaves with a cloth. Don’t wash them, don’t crush them, any black veins in the leaves can compromise the taste and colour of the pesto.
Pound the peeled garlic with a pinch of salt. Then add the basil. Pound the basil gently.
Pound until you obtain a dark green, liqueur-like mixture.
Now add the Pan pine nuts and pound them in the mortar.

When the mixture is well blended, add the parmesan and pecorino mix alternating with a little oil, pound and continue alternating cheese and oil.

The final mixture should have the typical grainy, creamy consistency.