Preheat your oven to 375 degrees and spray a casserole dish with cooking spray.
Season your chicken with the creole seasoning, salt and pepper (if needed), and thyme on the front and back. Prep all the veggies next and put them in a bowl off to the side.
Heat a deep pan with the peanut oil on medium high heat. Once warm, add the chicken, skin side down to the pan. Cook each side for 3-4 minutes or until golden brown. Once brown, take off the pan and let it cool on the side.
Add the butter to the pan and let brown slightly, swirling it around. Add the onions and carrots to the pan, season with salt & pepper, and cook for 6-8 minutes until soften. Add celery and garlic and continue to cook down. While the vegetables are cooking, remove the bone from the chicken and chop up into small pieces.
Once the veggies have cooked down a bit, about 15 minutes, remove the veggies from the pan and add them to a bowl. Drop the heat to medium low, adding the flour to the bottom. Using a whisk, stir the flour and scrape the bottom of the pan slightly to begin the roux. Slowly begin to add the chicken stock, about a cup at a time. Continue to stir the mixture until it thickens. You want to use enough chicken stock to create a thick sauce that will cover all of the veggies and chicken. Depending on the amount you add, you'll need 2-4 cups of chicken stock.
Add the veggies and chicken back to the mixture. Stir to coat in the chicken stock mixture. Season with Salt & Pepper to taste. Heat the mixture for about 5 minutes. Add the peas right before you remove from heat.
While the mixture is cooking, sprinkle some flour on a board and roll out your pie crust to fit the size of your casserole dish. To transfer, use your rolling pin and roll the pie crust onto the rolling pin (see picture above).
Remove mixture from heat and transfer to casserole dish, spreading it out evenly. Very carefully, pick up the rolling pin with the pie crust and slowly unroll it onto the top of your dish. Using a fork or your fingers, create a crust around the edge. Create an egg wash with one egg and a little water, brush this onto the unbaked crust, sprinkle salt to finish, and cut a few small slits into the crust.
Bake for 45-50 minutes, or until crust is golden brown.
Let cool for 5 minutes before serving. Using a serving spoon, cut into the crust and scoop out some chicken pot pie onto a plate, sprinkle with parsley to finish, grab a fork, and ENJOY!