In a large pot, heat olive oil over medium heat. Add diced chicken and cook until browned, about 5-7 minutes.

Add carrots, celery, and peas to the pot. Cook for an additional 5 minutes, stirring occasionally.

Stir in the orzo, chicken broth, garlic powder, onion powder, salt, and pepper. Bring to a boil.

Reduce heat and let simmer for about 10-12 minutes until orzo is tender.

In a small bowl, whisk together heavy cream and flour. Stir into the pot and cook for another 2-3 minutes until thickened.

Preheat the oven to 400°F (200°C).

Transfer the mixture to a baking dish. Roll out the puff pastry and place it over the filling. Trim excess pastry and cut slits for steam.

Brush the pastry with beaten egg. Bake for 20-25 minutes or until the pastry is golden brown.