Step 1

In a food processor, place the flour and baking powder. Pulse for one second to combine. Add the butter and pulse for a few seconds at a time, until the mixture has a coarse and grainy texture. Add the egg, water and vinegar, pulsing a few seconds at a time, until a ball begins to form. Remove the dough from the processor. Form into a ball with your hands, dust with flour and cover with plastic wrap. Refrigerate for about 1 hour.

Step 2

In a bowl, combine the egg and milk. Set aside.

Step 3

In a skillet, brown the onions and garlic in the oil. Add the mushrooms and cook until their water has evaporated. Add the ground pork and cook, breaking it up with a spoon, until cooked through. Season with salt and pepper. Let cool. Add the remaining ingredients and stir to combine.

Step 4

With the rack in the lowest position, preheat the oven to 350°F (180°C).

Step 5

Roll out the dough. With a 5-inch (12.5 cm) round cookie cutter, cut 12 circles of dough. Line 12 muffin cups with the circles.

Step 6

Spoon the filling into the dough. Brush the edges of dough with the egg wash.

Step 7

With a 3 ½-inch (9 cm) round cookie cutter, cut 12 circles of dough. Place on the meat pies. Seal. Make an incision in the centre of each meat pie.

Step 8

Bake for about 45 minutes or until the pastry is golden brown. Immediately unmould the meat pies and serve warm.