01 -
Season chicken breasts with salt and pepper. Place in a large saucepan and cover with water. Bring to a simmer and cook until just cooked through. Remove chicken, allow to cool for a few minutes, then chop into bite-sized pieces. Reserve 1 3/4 cups of the cooking water and discard the rest.
02 -
In the same saucepan, add butter, chopped onion, and sliced celery. Cook over medium heat until vegetables soften and become translucent. Stir in flour, salt, pepper, garlic powder, celery seed, and chicken bouillon paste until combined. Gradually whisk in reserved water and milk, simmering over medium-low heat until the mixture thickens.
03 -
Add chopped chicken and frozen mixed vegetables to the thickened sauce. Adjust seasoning with additional salt, pepper, bouillon, or garlic powder as desired. Remove from heat and allow filling to cool to room temperature before assembling.
04 -
Preheat oven to 425°F (220°C).
05 -
On a lightly floured surface, roll one chilled pie dough into a 12-inch diameter circle. Transfer dough to a 9-inch pie pan, fitting it into the dish evenly.
06 -
Pour the cooled chicken and vegetable filling into the pie crust. Roll out the second pie dough to cover the filling. Seal and crimp the edges of the two crusts together. Cut a small slit on the top crust to allow steam to escape during baking.
07 -
Whisk together 1 egg and 1 tablespoon of milk. Brush a thin layer over the top crust to promote browning.
08 -
Bake in the preheated oven for 40 to 50 minutes, or until the crust is golden brown and the filling is bubbly. If the crust browns too quickly, cover it loosely with aluminum foil to prevent burning.
09 -
Allow the pie to rest and set for 15 to 20 minutes before slicing and serving.