Preheat oven to 190°C (375°F)
Heat butter and olive oil in a pan then sauté onion garlic and carrots until soft
Stir in flour and cook for 1–2 minutes
Slowly add chicken broth and milk stirring until thick and creamy
Add shredded chicken peas thyme rosemary salt and pepper then mix well
Roll out pie crust and place bottom crust in baking dish if using
Pour filling into the crust evenly
Cover with top crust then seal edges and cut small slits on top
Brush with beaten egg for golden color
Bake for 35–40 minutes until crust is golden brown
Let cool slightly before serving