Pre-heat the oven to 400*F.
Add the dry ingredients to a bowl and whisk to combine.
Add the cold grated butter and gently stir until the mixture is shaggy.
Add the ice water and stir just until the dough is clumpy and moist enough to be formed into a rough ball (the butter will moisten the dough more as you roll the dough).
Pour the clumpy dough out onto a large greased and well coconut floured piece of parchment paper or clean greased and floured counter top.
Form the dough into a rough ball shape and sprinkle it with coconut flour. Top the dough with another greased piece of parchment paper and roll it out into a rough flat rectangle.
Fold this rectangle in half and again sprinkle both underneath and on top of the dough with coconut flour and roll it out into a rough rectangle. Repeat this process 4-5 times or until the dough holds together nicely (don't over-do it because you still want the dough to be relatively cold). See above for my tips on using my pastry method for an even flakier crust.
On the final time you roll out the crust, do your best to form it into a circle (it does not have to be perfect).
Place your finished pastry on top of the chicken pot pie filling, gently folding in the edges (if you wish) to resemble traditional pie crust (see photo).
Brush the crust a mixture of 1 egg yolk whisked with 1 tbsp water and make 3 fork holes in the center of the pie crust.
Bake the pie for 30-40min or until the pie is browned on top and heated through. I recommend covering the top of the pie pan with tinfoil if baking past 28min if you wish to prevent it from browning too much (but also note, this crust looks like it's browned more than it really is so don't be deceived, it won't taste burnt even if it's quite a deep brown).
Let the pie cool slightly before slicing and serving. Enjoy your Keto Chicken Pot Pie!