Clean and chop all the vegetables.

In a large saucepan or wok which has a lid, add the chicken, mushrooms, leeks, along with the cup of water, garlic, thyme, parsley, bay leaf, salt, and pepper.

Put the lid on the saucepan and cook at medium-temperature for 15-20 minutes, or until the chicken looks cooked.

Shred the chicken into small pieces.

Mix the flour in a bowl with a tablespoon of water so that it creates a roux.

Add the roux to the saucepan

Add creme fraiche into the saucepan and mix.

Remove the bay leaf from the chicken pie filling.

Let the chicken pie filling rest for 5 minutes.

Preheat the oven to 375°F (190°C) for 5 minutes.

Lightly grease a large casserole dish that can go in the oven.

Roll out the pie base in the casserole dish.

Gently spoon the chicken pie filling on the bottom layer of the pie dough crust.

Once all the the chicken filling is in, top with the 2nd pie crust.

Crimp the edges of the two pie crusts together all the way around with your fingers.

In a small bowl, mix the egg white and baste the top of the pie lightly with a pastry brush.

Slice small slits on the top of the chicken pie.

Place in the oven for 45-50 minutes until the top has risen and is golden brown.

Serve while warm.