Take your disc of pastry dough out of the refrigerator and let it soften to room temperature. It should be pliable enough to easily press your finger into the surface, but not so warm that it feels greasy.
Set a piece of parchment paper, 12x16 inches (half sheet size; 30x40cm) on a flat work surface. Lightly dust the parchment paper and both sides of your dough with flour.
Using the heel of your hand, gently press the dough out into a circle about 1 inch (2.5cm) thick. If cracks start to form at the edges, press the dough back together with your hand.
Flip the disc of dough over, dusting both sides lightly with flour again. Using a rolling pin, roll the dough out into a circle about 12 inches (30cm) in diameter and 3-4mm thick.
Flip your tart or pie tin upside down, centered over the circle of dough.
Very carefully but with some speed, flip everything over so the tin is right side up with the dough centered on top of it.
Carefully peel the parchment paper off of the shortcrust pastry dough.
Gently push the dough into the pie tin and trim away any excess. If there are any cracks, press some of the excess dough into that area.