Step 1

Preheat the oven to 425 degrees F (220 degrees C).

Step 2

Place 1 pie crust in a 9-inch pie plate. Poke several holes in the bottom of the crust.

Step 3

Bake crust in the preheated oven for 5 minutes. Remove and set aside to cool.

Step 4

Heat oil in a medium skillet over medium-high heat. Season both sides of chicken breasts with rosemary, parsley, salt, and pepper. Add chicken to the skillet and saute until golden brown, 2 to 4 minutes per side.

Step 5

Reduce heat to medium-low and add 2/3 cup chicken broth. Simmer, being careful not to overcook, just until chicken juices run clear, 10 to 15 minutes. Transfer chicken to a plate, allowing it to cool until the juices settle, about 15 minutes. Reserve pan drippings.

Step 6

Meanwhile, melt butter in a large skillet over medium heat. Add pan drippings and garlic. Saute until garlic is fragrant, about 30 seconds. Add onion, salt, and pepper and cook until onion is translucent, about 5 minutes. Whisk in flour until mixture thickens.

Step 7

Add 1 3/4 cups chicken broth and milk, 1 cup of liquid at a time, whisking constantly. Remove from heat once mixture begins to thicken.

Step 8

Cut chicken into bite-sized pieces and mix with thawed vegetables and broth mixture until combined. Pour into the pre-baked pie crust. Cut slits in the remaining pie crust and place it on top of the pie, crimping the edges to seal and decorating them with tongs or a fork, if desired.

Step 9

Place pot pie in the oven and bake until crust is golden brown, 30 to 40 minutes. Check edges halfway through baking time and cover them with aluminum foil if they start to brown too much.