One-Skillet Chicken Pot Pie

Heat the oven to 425°F. In a cast iron or oven safe pan, melt the butter. Add the veggies (carrots, celery, onion) and cook until soft. Add the flour, salt and pepper, celery salt, garlic powder, mix together and cook for 2 minutes. Slowly incorporate the milk and then the chicken stock. Add the peas and chicken. Top with the puff pastry or crust. Whisk an egg and baste the top, then bake for 25 minutes. Time to eat!