Mix softened Butter and Sugar until smooth. Add Egg Yolk and mix until creamy.
Add Plain Flour and mix as you cut the butter mixture into flour. After mixing, it might look too DRY, but do not add Water. Use your hands to bring the mixture together into dough.
For tart/pie base, simple spread the dough in a baking dish evenly and press using your fingers. If you want to roll the dough into a sheet, place the dough between 2 sheets baking paper, roll until 3-4mm thick, then refrigerate until firm.
For cookies, place the dough on a sheet of plastic warp, shape into a log, and wrap. Refrigerate until firm. When it is firm, remove and discard the plastic wrap, and slice the dough into 8mm thick rounds. Bake in 170℃ oven.
