• In a large bowl mix the flour, salt and sugar. Add the cold, cubed butter to the bowl and use your fingertips to rub the butter into the dry ingredients until sandy. Drizzle some of the cold water into the bowl, mixing in with your fingertips and lightly kneading (adding more water if it seems dry) until the dough comes together. 
• Pat the dough into a circle and then place in the silicone dough rolling bag. Place into the fridge to chill for an hour. 
• Remove the pastry from the fridge. Keeping it inside the silicone dough rolling bag, roll the pastry out into a circle 12-inches in diameter. Unzip the bag and flip the dough into an 8-inch pie tin. Trim excess pastry from around the edges and crimp decoratively if you'd like. Place in the freezer for 15 minutes. 
• Preheat the oven to 160oC convection (180oC/350oF). 

Meanwhile make the filling:

• In a small pot melt together the butter, maple syrup, milk, brown sugar and salt. Once the butter has melted and the mixture starts to bubble, take it off the heat. Allow to cool slightly before quickly beating in the eggs and folding in the pecans. 
• Remove the lined pie tin from the freezer. Scatter the chocolate chunks over the base and pour in the filling. Bake for 35-40 minutes until golden on top with a golden-brown crust. Remove from the oven and leave to cool for 10 minutes at least until cutting and serving.