Add the flour to a mixing bowl and make a well in the middle. Mix together the water, olive oil and salt and pour into the well. Start incorporating the flour into the water/olive oil/salt mixture until a dough starts to form.
Once it forms, take the dough out, transfer to a clean table and start kneading it until it becomes smooth. With a rolling pin, shape it into a rectangle about 2cm thick, wrap in cling film and leave to rest for at least 30 minutes somewhere cool.
To make the pici, cut the dough into 15g strips (weigh one to check and use as a guide) and keep covered with a damp tea towel. On a dry, clean work surface – stainless steel or wood, you don’t want something too smooth as a little bit of friction helps – start rolling the strip outwards, with both palms of your hands, applying pressure evenly and pushing out, until you have a noodle the same thickness as a biro. Basically, you’re making wriggly worms. Repeat until all the dough is used up.
Cook straight away, or, if making in advance, store lengthways on a heavily floured tray (they stick together) covered with clingfilm and refrigerate for no more than 24 hours.