Fill a large bowl with ice and add water, set aside

Fill a medium sized saucepan with water and 12 ml of salt, and bring it to a boil

Remove the stems from the arugula and discard, add the leaves to the water, as soon as the water returns to a boil, remove the arugula with a slotted spoon and place it immediately into the ice water to stop the cooking process

Transfer the arugula to several layers of paper toweling or clean kitchen towels and allow to drain

Roll up the towels and squeeze as much moisture as possible from the arugula

Place the arugula in a blender jar, add the oil, 3 ml of salt and the pepper and purée until the mixture looks like thick pesto

There will be a small amount of oil on the surface

Use immediately or transfer the mixture to a jar with a tight fitting lid if you are going to store it

This will keep for at least 5 days, refrigerated

Before using, stir the pesto to incorporate the oil accumulated at the top.