Preheat your oven to 425 degrees.
Place the diced potatoes and carrots in a small saucepan, cover them with water, and bring to a boil. Let them soften for about 5 to 8 minutes.
Drain the softened potatoes and carrots, and set them aside. In a large sauté pan, melt 1/2 cup of butter over medium heat.
Add the diced onions and sauté for 2 to 3 minutes until they’re translucent and fragrant.
Next, sprinkle in the salt, ground pepper, dried thyme, and poultry seasoning. Stir to combine.
Sprinkle 1/2 cup of all-purpose flour over the mixture and cook for 1 minute, stirring constantly.
Gradually whisk in the chicken broth and then pour in the milk. Keep stirring until the mixture thickens into a creamy sauce.
Add the drained potatoes and carrots to the sauce, stirring to coat them with the creamy goodness.
Now, it’s time to stir in the shredded chicken and peas. Turn off the heat and mix everything together until well combined.
Fit one of the refrigerated pie crusts into the bottom of a deep dish pie plate. Pour the creamy chicken filling into the crust.
Place the second pie crust on top of the filling. Trim any excess dough hanging over the edge and press the two crusts together to seal.
Brush the top crust with the egg wash made from the beaten egg and water. This will give your pie a beautiful golden color.
Using a sharp knife, cut four slits in the top crust to allow steam to escape during baking.
Finally, place the assembled pie on a baking sheet and bake in the preheated oven for about 30 minutes or until the crust is golden brown and the filling is bubbling.
