Combine the flour and chilled butter in the bowl of a stand mixer. Break the butter into the flour using your fingers until it resembles wet sand.

Add the sugar, salt, egg, and water. Keep mixing together the ingredients with your hand until a wet dough paste comes together.

Knead with the dough hook attachment on setting 4 for 15 minutes, or until the dough is smooth and elastic. (*Footnote 2) Carefully pinch the dough with your fingers and it should form a thin semi-transparent sheet.

Cover the dough with plastic wrap and rest for 15 minutes.

Add the ingredients for the oil dough into a medium-sized bowl.

With a spatula or by hand, mix until a smooth dry paste is formed.

Transfer to a clean working surface. Press into a 6” x 6” (15cm x 15cm) square. Cover with plastic wrap and rest for 10 minutes.

Once both doughs are rested, dust the work surface with flour. Gently knead the water dough for a few times until it forms a 6” (15 cm) smooth round ball.

Use a rolling pin to flatten the dough into four directions about 4” (10 cm), forming a cross shape, leaving the center thicker and shaped like a 6” (15 cm) square. Once done, it should create a 4-sided cross shape. Gently roll the square center a few times to smooth it out.

Place the oil dough in the center aligned with the square. Fold the four sides over the oil dough, one side at a time, so they are overlapping, while using your palm to press the dough gently to press out as many air bubbles as you can. Gently smooth out and pinch the dough together to seal.

Dust the working surface again. Flip the dough over. Gently roll into a 8” x 18” (20cm x 45cm) rectangle.

Fold the short sides of the rectangle inward, leaving about one finger’s width in the middle. Fold the dough in half again along the short side, as if closing a book..

Dust the dough with flour again. Place the short side of the folded dough towards you. Repeat the rolling and folding from the step above.

Cover the folded dough with plastic wrap. Let rest for 15 to 30 minutes at room temperature, or in the refrigerator if the dough feels soggy or loose.

At this stage, the dough can be stored in the refrigerator for a few days for later use. Just make sure it is well wrapped and sealed (you can store the wrapped dough in a ziplock bag or a container).

While the dough is resting, make the filling: Combine the hot water and sugar in a medium-sized bowl. Stir until the sugar is dissolved. Set aside to cool.

Add the eggs to a medium-sized bowl with a pinch of salt. Beat the eggs gently with a fork until it is consistent but not frothy.

Add the evaporated milk to the cooled sugar syrup. Stir to mix well.

Then pour the syrup mixture into the eggs. Gently mix again until everything is well combined.

Strain the egg mixture through a fine mesh strainer (or a regular mesh strainer lined with cheese cloth) into a container or measuring cut that’s convenient for pouring.

Preheat the oven to 325°F (162°C).

Cut the dough into two equal pieces. Wrap the half not in use with plastic wrap and store it in the fridge.

Roll the other half of the dough into a 1/8” (3 mm) thick rectangle.

Using a large, round pastry cutter (5 3/8”, fluted if possible) cut out 8 circles of dough.

Work on one piece of dough at a time. Carefully lift each circle and place it into a pastry cup. Gently drop and tap the cup to help the dough fall into place. Once the dough is mostly in place, gently press the bottom and sides into the cup, until the edges are slightly over the top of the pastry cup. Don’t press the sides too hard as it can damage the layers. Aim to have a small lip over the side of the cup, since the dough shrinks as it cooks.

If you plan to make the full batch, repeat the shaping method to work on the second half of the dough. Meanwhile, cover the assembled pastry cups with plastic wrap to prevent them from drying out.

Right before baking, place the assembled tart shells on a baking tray. Fill each cup with the filling, leaving a 1/4” (0.5 cm) space at the top, about 2 1/2 tablespoons.

Bake the tarts at 325°F(162°C) for 25 to 35 minutes, until the custard is set and does not jiggle when moved.

Let the egg tart cool off a bit before serving. You should serve them as fresh as you can.

Once the egg tarts have cooled completely, you can store them in an airtight container in the fridge for 2 to 3 days. Their taste will diminish the longer you store them, but mine tasted quite nice the next day. During the first two days, the crust will keep quite crispy in the fridge and the filling moist.