Sift flour and salt into a mixing bowl and add the oil. Gradually add the water and start kneading as you add the water. Combine and knead to form a soft dough.
The dough will feel sticky at first, but kneading, it should develop into a dough that becomes smooth and satiny. Cover the dough and let it rest at least for 1 hour.
If not all the dough is being used right away, wrap the unused portion and keep chilled in the fridge up to a week. Always bring to room temp before using.
Divide the pastry into 12 equal portions, shaping them into smooth balls. Cover with a cloth, except the one you're working with.
Mix 1 tsp cornstarch and 1tsp flour together in a bowl. Dust a work surface and the first dough ball with the cornstarch mixture. Flatten out the dough ball and roll out into a circle, about 5 inches in diameter. Dust again with cornstarch mixture. Set circle to one side. Roll out 4 more dough balls to about the same diameter and stack them on the first one, dusting each layer with more of the cornstarch mixture to keep them from sticking together.
When you have 5 circles, roll out the stack to a larger circle about double in size, turning as you go to maintain a round shape. Separate each layer and layout the circles. Re-apply more cornstarch mixture where needed and re-stack them.
Roll again until the 5-layer stack is paper-thin, about 10 to 12 inches in diameter. Place on a sheet of parchment paper; top with another piece of parchment. Gently roll up the dough; wrap in plastic wrap. Refrigerate.