01 -
Preheat oven to 400°F (200°C).
02 -
In a large skillet or saucepan, melt butter over medium heat. Add onion, garlic, carrots, and celery. Cook for 5–7 minutes until softened.
03 -
Sprinkle in the flour and cook for 1–2 minutes, stirring constantly.
04 -
Gradually whisk in chicken broth, then milk. Cook until the mixture thickens and bubbles.
05 -
Stir in shredded chicken, peas, salt, pepper, and thyme. Simmer for 2–3 minutes, then remove from heat.
06 -
Transfer the filling into a 9-inch pie dish or baking dish.
07 -
Cover with puff pastry or pie crust, crimping the edges to seal. Cut a few slits in the top for steam to escape.
08 -
Brush the crust with beaten egg.
09 -
Bake for 30–35 minutes or until crust is golden and filling is bubbling.
10 -
Let rest for 5–10 minutes before serving.