Make the char siu filling:

• Heat 1 teaspoon of avocado oil in a frying pan over medium heat.
• Add in the shallot, and sauté for 1-2 minutes, until lightly softened.
• Next, add in the diced char siu and stir for another 1-2 minutes.
• Add in the soy sauce, sugar, black pepper, tapioca starch dissolved in 1 tablespoon of cold water. Give it a stir.
• Bring the mixture up to a simmer, and then drizzle in 1 teaspoon of sesame oil.
• Remove from heat and let cool.

Make the pastry dough:

Water dough:

• In a bowl, combine the all-purpose flour and cold salted butter. Use a fork to cut the butter into the flour.
• Add in the avocado oil and water.
• Mix until the dough comes together.
• Add 1 teaspoon of all-purpose flour and knead until the dough becomes smooth.
• Cover with a damp cloth and let it rest for about 20 minutes.

Oil dough/paste:

• In a small bowl, combine the cake/pastry flour together with the oil.
• Stir with a spoon until it becomes a smooth paste. Set aside.

Assemble:

• Divide the water dough into 10 equal portions.
• Roll out the dough into a flat square.
• Spread 1 tablespoon of oil paste in the centre of the dough (be careful not to get to close to the edge).
• Fold over dough in half and press down to seal the seams.
• Gently press down the dough and flatten.
• With a rolling pin, roll the dough out into a slender rectangle.
• Coil the dough up (like making a jelly roll) and turn it 90 degrees. Flatten and repeat.
• Roll out the dough again, coil it up and turn it 90 degrees another 2 more times. (This produces the flaky layers).
• Once the dough is rolled out to a long rectangle, add 1.5 teaspoon of (about 18g) of char siu filling to the centre.
• Fold up the dough to cover the filling and seal/crimp the edges with a fork.
• Place the pastry onto a parchment-lined baking sheet.
• Repeat with the remainder.

Bake:

• Preheat oven to 400°F/204°C.
• Brush the tops of the pastries with lightly beaten egg (egg wash).
• Sprinkle with sesame seeds (optional).
• Bake at 400°F/204°C for 5 minutes, and then reduce to 350°F/177°C for another 20-25 minutes, until puffy and golden brown.
• Serve warm.