Preheat oven to 400 degrees F. Lightly grease a 12" x 17" sheet pan.
Melt butter in a 4-5 quart saucepan or high-sided skillet over medium heat. When butter starts to bubble, add carrots, celery and onion, stirring well to combine. Cook for 5 minutes, stirring occasionally, till vegetables are crisp-tender.
Stir in flour, and black pepper until vegetables are well coated. Slowly add broth, then cream, stirring to combine. Once the mixture starts to bubble, lower the heat and cook 6 minutes, until slightly thickened, stirring occasionally. Stir in chicken and peas. Remove from heat, taste, and add more seasoning if needed. Pour filling into prepared pan and let cool 15 minutes. You don't want to put the crust on a hot filling, or it will begin to melt before it gets in the oven to bake properly.
Roll pie dough out to slightly larger than the pan. Lift dough by either rolling it around the pin, or folding it in half, and place on top of the filling Tuck the overhanging edges under, pressing to create a standing border. Cut decorative slits on top of crust to let steam escape. Brush crust with egg wash. Bake until golden brown and bubbling, 35-40 minutes, rotating once near the end of baking, if needed, for even browning.
Notes:
- You can easily replace the chicken broth and light cream with other liquids, as long as the total quantity remains the same. Just be sure to use low-sodium products, as the Provencal Seasoned Salt contains all the salt you'll need.
- If you don't have a sheet pan, feel free to use whatever dishes you do have.
-This recipe makes about 8 cups of filling. If you want to halve the recipe, count on 4 cups of filling.
- If you want to use frozen peas and carrots, a 1 lb. bag provides the right amount. Add them to the recipe at the end of the cooking time, after sauce has thickened.