1-First Steps: Preparing the Chicken and Oven Begin by seasoning your 1 pound of boneless, skinless chicken breasts with 1/2 teaspoon salt and 1/4 teaspoon black pepper. Simmer them in water until they’re cooked through, which usually takes about 15-20 minutes. Once done, let the chicken cool, then chop it into bite-size pieces and set aside some of the cooking water for later about 1 to 2 cups will work well.

2-Making the Filling: Next, in a large skillet, cook 1/3 cup chopped onion, 1/2 cup sliced celery, and 1/3 cup butter over medium heat until the veggies soften, about 5 minutes. Stir in 1/3 cup all-purpose flour, along with the remaining salt, pepper, 1/2 teaspoon garlic powder, 1/4 teaspoon celery seed, and 1 teaspoon bouillon paste or cube. Gradually whisk in the reserved cooking water and 1 cup milk, stirring until the mixture simmers and thickens into a smooth sauce. Once thickened, mix in your chopped chicken and 8 ounces of frozen mixed vegetables. Taste and adjust the seasoning if needed this is where you can add a pinch more salt or pepper to suit your taste. Let the filling cool a bit before moving on, as this helps when you assemble the pie.

3-Assembling and Baking: Roll out one portion of your chilled pie dough and fit it into a 9-inch pie pan. Pour in the cooled filling, then roll out the second portion of dough and place it over the top. Seal the edges carefully and cut a slit in the top to let steam escape during baking. Whisk together 1 egg and 1 tablespoon milk for an egg wash, then brush it over the top crust to give it that golden shine. Bake at 425°F (220°C) for 40 to 50 minutes until the crust is golden and the filling bubbles. If the edges brown too fast, cover them with foil to keep everything even. Let the pie rest for 15 to 20 minutes before serving, which allows the flavors to settle.