Preheat oven to 180°C (350°F, gas mark 4) and sprinkle with rock salt a baking tray

Wash the potatoes, pat them dry, pierce with a fork and arrange them on the salt. Bake for about an hour or until soft if pierced with a knife. Let them cool slightly, peel them and mash with a potato masher or a food mill.

Add a lightly beaten egg, salt and a pinch of grated nutmeg (or more if you like the taste), then knead to mix all the ingredients.

Pour half of the potato flour on a wooden board, add the mashed potatoes and cover the dough with the rest of the potato starch. Work the mashed potatoes with a spatula until the starch has been incorporated and the dough is smooth.

Shape the gnocchi by rolling small balls of dough between your hands, previously sprinkled with potato starch. Gave them the shape and size of a hazelnut and arrange the tiny gnocchi on a large tray sprinkled with potato starch.

Now make pesto. Dice the courgette and add it in a blender with pistachios, mint leaves, extra virgin olive oil and salt. Blend until smooth.

Cook the gnocchi in boiling salted water until they'll float up to the surface, a couple of minutes will be enough. Drain the gnocchi and season them with the freshly made pistachio pesto. Add some coarsely chopped pistachios for decoration.