Flatten the water dough and place another piece of cling film on top.
07Roll the water dough to form a large square.
08Remove the cling film on top of the water dough, place the oil dough in the center and fold the sides of the water dough over the oil dough. Make sure the oil dough is fully covered by the water dough. Flatten it with a rolling pin. (Analogy: Now the dough looks like a sandwich, with the oil dough mirrors the filling of the sandwich, and the water dough mirrors the bread.)
09Wrap it in cling film and leave it in the chiller for twenty minutes or until it hardens.
10Remove it from the chiller Flatten it with a rolling pin to about 3cm thick. Fold both ends of the dough toward the center like closing a book. (Analogy: Now it resembles a multilayered sandwich.) Place it into the chiller again for 20 minutes.
11Repeat the folding process (step 6) three more times.
12After the last repetition, flatten the dough to about 3mm thickness. Use a cookie cutter or bowl to cut out pieces of round pastry that are slightly larger than the area of the mold.
13Put the cut pastry into a mold. Lightly press the pastry onto the surface of the mold.
14Trim the sides with a fork or a blunt knife.
15Melt the sugar with water to make a simple syrup. Let it cool.
16Beat the eggs for a minute.
17Add the milk and syrup to the egg. Mixed well.
18Filter the milk liquid twice to remove impurities.
19Fill each empty pastry shell up to 70%.
20Bake it at 200 degrees C/ 390 degrees F for 15 minutes, then reduce to 180 degrees C / 356 degrees F for another 10 minutes. Leave the oven door ajar for five minutes then remove the egg tarts.