To make a good pie, you need to have a pastry (shortcrust, shortbread, sweet or other...) that is rolled out thinly, i.e. about 3 mm thick.
It must be rolled out thinly, but also regularly, in other words the thickness must be the same on the whole surface of the dough.
It's not that easy to roll out a dough evenly, and the professionals who do it often work with a rather extraordinary machine called a rolling mill: The dough is pushed by an automatic belt between 2 metal cylinders of adjustable thickness.
At home, there is no secret, you have to work with a roller and therefore spread your dough a little by eye to determine the right thickness, and be as regular as possible.
Can we improve this?
Yes, and with a very simple and inexpensive tool, the
pastry wedges.
As their name indicates, they are very simple blocks, in different materials, metal, silicone, wood... and of fixed thickness, often 3, 5 and 10 mm.
To use them, you just have to start rolling out as usual, then when you are close to the chosen thickness, put the wedges around the dough, and pass the rolling pin by leaning on the wedges.
This way, the roller can't go lower than the wedges, and your dough can't go lower in thickness than the wedges.
It's both very simple and very effective, so don't hesitate to try it.
To sum up: To roll out a dough evenly, nothing is more practical than pastry blocks of the chosen thickness.