Prior to using, cool the flour in the refrigerator.
Mix the egg yolk, salt and sugar well together, and refrigerate.
Dice the butter into 1.5 cm cubes and refrigerate.
Place the flour and butter in a bowl and, using a mixer, rub the fat into the flour. Do not overbeat the flour and butter, which would make the mixture wet.
Add the liquid and mix roughly. Do not overwork, which would allow the gluten to develop.
Spread it out onto greaseproof paper, wrap it and leave it to chill in the refrigerator overnight.
Roll it out to a 2.5 cm thickness and use to line the buttered tart ring. If your tart ring is deep and difficult to line, you can line the base and sides separately.
Spread out some paper over the inside of the tart case, weigh down with baking beans and bake at 180 °C until lightly coloured. Remove the baking beans and brown further to seal.