Place some ice cubes in a deep plate and add the basil leaves. Let them sit for about 10 minutes to help keep the basil a vibrant green. Once ready, gently pat the leaves dry with a towel to remove excess water.

In a mortar, crush the garlic cloves. Once crushed, add the pine nuts and grind until you have a creamy mixture.

Add the coarse salt and basil leaves to the mortar.

Start by pounding the ingredients, then use a circular motion to blend. Use a spoon to scrape the sides of the mortar so everything mixes evenly. When the mixture is creamy and smooth, add the Pecorino cheese pieces and continue grinding to incorporate, then add the Parmesan cheese.

Once everything is blended into a creamy paste, pour in the olive oil and stir with the pestle for a few more moments. Your pesto alla Genovese is ready to use!