place the flour, margarine and salt in a bowl
Crumble the whole thing by hand
Gradually add the water (about 50 ml), mixing until the dough forms a soft but not mushy ball, stopping as soon as the dough forms a ball and is no longer sticky!
Press the dough into quarters on a lightly floured work surface, then cover with a thin layer of flour and a tea towel.
Set aside in a cool place for 20 to 30 minutes, ensuring a minimum rest period of 20 minutes.
Line a lightly greased baking tin with the pastry, then press gently to ensure it adheres perfectly.
Trim the excess pastry by running a knife along the edges of the tin or rolling a rolling pin over the top to form a slight bead.
Prick the pastry with a fork, then garnish as desired.