To make the pesto, in a pestle and mortar, smash the garlic and a pinch of sea salt into a paste. Tear in the top leafy half of the parsley and bash again until pulped, followed by the pistachios.
Finely grate in the pecorino or Parmesan cheese, muddle in the lemon juice and 2 tablespoons of extra virgin olive oil to loosen, then season to perfection, tasting and tweaking.
Spoon the pesto over a serving plate. Top with the baby mozzarella (drained), or you could tear over a ball of buffalo mozzarella or burrata.
Finish with a drizzle of extra virgin olive oil, and I like to add a few extra chopped pistachios and parsley leaves to tell the story.