Finely chop the leek, onion and apple. Heat up some olive oil in a deep pan, then set the vegetables and apple to seer.
Chop the pork steak into small cubes and add over the vegetables. Add your condiments and mix well.
Pour your water over the mixture and add the chicken stock cube. Mix well to melt the stock.
Cook over medium heat for 5-10 minutes, mixing to prevent sticking.
In a separate bowl add a splash of water and mix in the cornstarch to make a paste. Add cornstarch mixture over the meat and mix continuously until the liquid hardens up. It should still be nice and smooth, not clumpy. Add more water to get a semi-runny consistency.
Assembling the Pork Pie
Pre-heat oven to 180°C (360°F) fan-assisted.
Divide your dough in half - one larger piece (⅔) and a slightly smaller one (⅓).
Gently flour your work surface, the roll out the larger dough using a rolling pin. We are aiming for a 3mm (⅛ inch) thickness, to have a lovely thin pastry.
Use a round scone or cookie cutter (around 10cm in diameter) to cut out 12 circles. Re-roll any spare pastry to make more circles if you're short of 12.
Grease a 12 slot cupcake/muffin tin, then place each circle in a slot, pressing gently with your fingers to fit it into place.
Add the pie filling in the middle, almost up to the brim, but not higher than your pastry.
Roll out the smaller remaining piece of dough with a corrugated edge cookie cutter, the same size as your tin slots.
Place each circle over the pie filling, pressing on the sides to seal the pie edges.
Make a small hole at the top of the pie to allow steam to escape. Brush each mini pie with egg wash for a lovely shiny finish.
Bake for 40-45 minutes or until golden-brown in colour. Once baked, let the pies cool in the tray for 20 minutes, then transfer to a wire rack.
Notes
I recommend using a kitchen scale in grams for more accuracy. The cups used for the conversion are standard US customary cups (1 cup flour = 136g). There are many different types of cups across the globe, which is why I strongly recommend using grams instead.
The amount of water required can depend very much on the type of flour you use and how much protein in contains. You may need to adjust by adding more or less water by 1-2 tsp. The dough needs to hold together, but not be overly sticky or too crumbly.
Adding fresh herbs is entirely optional and can be adjusted to fit your recipe of personal preference. I like to add either coriander (cilantro in the US) or flat leaf parsley. You can also add thyme, oregano or basil.