1-Season the chicken breasts: Season the chicken breasts with salt and pepper, then place them in a saucepan. Cover with water and simmer until just cooked through, which should take about 15-20 minutes. Let the chicken cool, chop it into bite-sized pieces, and reserve about 1¾ cups of the cooking water for later.

2-In the same saucepan: cook the onions, celery, and butter over medium heat until they become soft and translucent, usually around 5 minutes. This step builds a flavorful base for your filling.

3-Stir in the flour, salt, pepper, garlic powder, bouillon paste, and celery seed: to form a roux. Cook this mixture for a minute or two until it’s bubbly, helping to thicken the sauce nicely.

4-Slowly add the reserved chicken cooking water and 1 cup of milk: stirring constantly. Simmer on medium-low heat until the mixture thickens, about 5-10 minutes, creating that creamy texture we all love.

5-Mix in the chopped chicken and frozen mixed vegetables. Taste and adjust the seasoning as needed, then let the filling cool before you assemble the pie to avoid a soggy crust.

6-Preheat your oven to 425°F (220°C). Roll out one piece of the homemade pie dough on a lightly floured surface to about 12 inches in diameter and fit it into a 9-inch pie pan.

7-Pour the cooled filling into the pie crust, then roll out the second piece of dough and place it over the filling. Seal and crimp the edges, and cut a small slit in the top for steam to escape.

8-Whisk the egg with 1 tablespoon of milk to make an egg wash, then brush it over the top crust for a golden shine.

9-Bake the pie for 40 to 50 minutes until the crust is golden and the filling is bubbly. If the crust starts browning too quickly, cover it loosely with foil.

10-Let the pie rest for 15 to 20 minutes before serving to allow the flavors to settle and make it easier to slice. For anyone adapting the recipe, remember to use gluten-free options as mentioned earlier.