For the crust: Mix flour and salt. Rub in the butter until the mixture is crumbly. Add 3 – 4 tbsp ice cold water to form the dough. Do not knead. Chill for 30 minutes, roll it out on a floured surface, fit it into a pie plate and trim the excess. Prick it with a fork. Bake in a preheated oven at 180°C/350°F for 15 minutes covered with tin foil and filled with uncooked beans to weigh it down and prevent it from rising. Then remove the beans and the foil, and bake for 5-10 more minutes until golden brown.