Begin by thawing the puff pastry at room temperature for about 40 minutes, or until it's still cool but pliable and easy to handle. Preheat your oven to 425℉.
1 sheet puff pastry
Melt butter in a cast iron skillet or stainless steel skillet over medium heat. Add the diced onion, carrot, celery, and kosher salt. Sauté for 5-7 minutes, or until the vegetables are softened and starting to brown.
4 tablespoons unsalted butter, 1 small yellow onion, 1 large carrot, 2 stalks celery, 1 teaspoon kosher salt
Add the minced garlic, poultry seasoning, and black pepper to the skillet. Continue to sauté for an additional 1-2 minutes.
4 cloves garlic, ½ teaspoon poultry seasoning, ½ teaspoon black pepper
Sprinkle in the flour, stirring it into the vegetables to create a roux. Cook for a few minutes to remove the raw flour taste.
¼ cup all-purpose flour
Slowly pour in the turkey stock while whisking continuously to prevent lumps from forming. Allow the mixture to simmer for about 5 minutes, or until it has thickened.
2 cups turkey stock
Stir in the shredded turkey and peas, cooking for an additional 2-3 minutes. If you're using a pie plate, transfer the filling to it at this point.
3 cups shredded turkey meat, ½ cup peas
While the filling cools slightly, prepare the puff pastry by unfolding it and pinching together any parts that may have split. You can also cut a decorative pattern into the puff pastry if desired, then place it on top of the pie filling.
To prevent spills in your oven, place the cast iron skillet or pie plate onto a baking sheet. Bake the pot pie for 20-25 minutes, or until the puff pastry is golden brown and the filling is bubbling. If the edges of the puff pastry begin to brown too quickly, cover with foil for the remaining bake time.
Remove the pot pie from the oven and allow it to cool for 20-30 minutes before slicing and serving. Enjoy!