Pasta with pistachio pesto

Method

1. 1 To make the pistachio pesto, start by putting a pan full of water on the heat, bring it to the boil and then tip in the shelled pistachios, cook them for 5 minutes or as long as it takes to soften the skins, then drain the pistachios.
2. 2 Remove the skins from the pistachios and gather them in a small bowl.
3. 3 Transfer the pistachios to a blender, pour in the olive oil, the grated Grana Padano, the basil leaves, half a clove of garlic and the grated zest of half a lemon.
4. 4 Run the blades for a moment and then pour in the water, add salt and pepper and run the blades again, blend the mixture until you have a smooth cream.