- Preheat oven to 425°F.
- Heat margarine in saucepan until melted. Stir in flour, salt, and pepper. Cook, stirring constantly until bubbly; remove from heat.
- Stir in broth and milk. Heat until boiling, stirring constantly. Boil for 1 minute.
- Stir in onions, vegetables, and chicken. Season with salt and pepper.
- Pour chicken mixture into pastry lined dish. Cover with remaining pastry. Pinch edges to seal crust.
- Bake at 425°F for about 35 minutes until top is golden brown and mixture is bubbly.