Place the very soft butter (but not melted) in the bowl of your mixer with the Confectioners Sugar and mix together with the leaf/paddle attachment until smooth.
Whisk the Egg and add it to the Sugar/Butter, along with the Almond Meal and Salt. Mix until combined.
Add the Flour in 2 times, mixing on slow speed until all incorporated (1).
Transfer the pastry dough over a large sheet of baking paper and assemble it into a ball. Gently flatten the ball into a disk using your hands, then place a second sheet of baking paper over the pastry.
Thinly roll the pastry between the two sheets of baking paper using a rolling pin (2) then place it over a flat tray in the fridge to chill and rest for at least an hour (and up to a day).
Take the pastry out of the fridge and leave it to come back to room temperature for about 5 minutes.
Remove the baking paper sheets (3) and transfer the pastry over the tart pan. You can use your rolling pin to help you transfer the pastry if needed (4)
Slide the pastry along the edges of the pan until it touches the bottom. Press it tightly against the bottom and edges of the pan (but without breaking it) to remove any air pockets. There should be no gaps between the pastry and the pan.
Remove any excess dough using the rolling pin and/or a small pairing knife (5). Use any excess pastry to patch up holes, cracks or irregularities if needed.
Poke the bottom of the pastry with a fork, then place the pastry in the freezer to set again.
Preheat your oven on 160'C/325'F while the pastry is in the freezer.
Bake the pastry for 20 to 30 minutes, or until the edges are golden and the pastry is dry to the touch. Leave to cool down completely before filling the tart case with your choice of creams and fruits.
This tart pastry will fit a 25 cm / 10 inch Tart Pan - or a slightly larger pan.
Do not overmix the dough here - you can stop as soon as you do not see large lumps or un-incorporated flour
The best way to roll the pastry is to always roll in the same direction. Simply turn the pastry 90' after each roll until you get a large circle. The pastry will be very soft - so easy to roll - but try not too roll it too thin. To check if it is rolled large enough, place the tart pan over and assess.
To make sure the pastry can be easily moved away from the baking paper sheets: remove the top sheet of baking paper, place it back over the pastry, flip the pastry over and remove the second sheet.
Roll the pastry around the rolling pin to easily move it. You might need to lightly flour the dough and/or rolling pin if the pastry seems sticky.
Roll the rolling pin over the top of the pan to cut off any excess pastry. You can also use a small pairing knife run parallel to your work surface to cut off the extra pastry.