1-3/4 cups plain flour
185 g cold butter, cut into cubes
2 tablespoons icing sugar
1 egg yolk
a little iced water if necessary
Put the flour, butter and icing sugar into a food processor and process until the mixture resembles breadcrumbs. Add the egg yolk and process until the mixture forms a ball; add iced water if necessary. Remove the dough from the processor bowl, wrap in plastic film and rest in the refrigerator for at least 1 hour.