Dice the well-chilled unsalted butter into 0.5-1 cm / 0.2-0.4 inch, and put it in a large bowl. Sift flour over the butter and use a scraper to cut butter cubes and mix.

Next, use your hands to rub the butter cubes until the mixture turns yellowish, looks like fine dry cheese powder.

Add granulated sugar and grated cheese. Use your hands to mix well while tossing the mixture.

Add the beaten egg and use a spatula to fold it. Fold until it forms many small lumps, and use your hand to press it and gather the dough.

Repeat "fold in half and press the dough" 4-5 times. Use your hands to press it into the tart pan and flatten it.

Cut it into eight equal parts. Use the thicker tip of a bamboo skewer to prick holes into each piece. Let it sit in a freezer for 20 minutes. Preheat the oven to 180℃ / 356 F.

Lower the oven to 160℃ / 320 F and bake for 40 minutes. Cut again the freshly baked along the traces of cuts while it's still soft.

Cool it for 15 minutes, and remove it from the pan. Transfer to a rack, and let it cool completely.
Please store them in a closed container. Thank you!