Preheat your oven to 400°F (200°C) and lightly grease individual pie dishes or one 9-inch pie dish.

In a large skillet, melt the butter over medium heat. Add the chopped onion and sauté until it becomes translucent, about 3–4 minutes.

Incorporate the diced carrots and potatoes, stirring occasionally, until they are tender, approximately 8–10 minutes.

Sprinkle the flour over the cooked vegetables, mixing for about a minute to cook off the raw flour taste.

Gradually whisk in the chicken broth, followed by the heavy cream. Allow this mixture to simmer until it thickens, about 3–5 minutes.

Stir in the cooked chicken, peas, thyme, and garlic powder, seasoning with salt and pepper. Let it simmer for an additional 1–2 minutes.

Roll out the puff pastry on a floured surface; cut circles to fit your pie dishes and spoon the filling into each.

Place the pastry over the filling, crimping the edges to seal them. Don’t forget to cut slits for steam to escape!

Brush the top with the beaten egg for a shiny, golden finish, and bake for 25–30 minutes, or until the pastry is beautifully golden. Allow it to cool slightly before serving.