Make the Filling:

1. In a Dutch oven, heat the oil over medium heat. Once hot, add the onion and carrot and cook for 5-7 minutes, or until they are beginning to soften. Add in the salt, pepper, and 1 tablespoon of rosemary, and cook for 30 seconds. Add the wine and continue to cook until it is mostly evaporated, about 3 minutes.
2. Add in the butter and flour and cook, stirring, until butter is melted.
3. Slowly stir in the stock, half a cup at a time, scraping up the bottom of the pot and stirring as you go to ensure no lumps.
4. Once all the liquid is added, add in the turkey and cranberries. Bring the mixture to a boil, then reduce the heat and simmer for 15 minutes, or until the sauce is thickened and the veggies are cooked through.
5. Shut off the heat, and stir in the peas, lemon juice, and remaining 1 tablespoon fresh rosemary. Taste and adjust seasoning, adding more salt, pepper, and/or lemon juice as needed.
6. Transfer the filling to a shallow container and let cool completely at room temperature, or overnight in the refrigerator.

Assemble and Bake:

1. When ready to bake, preheat the oven to 400ºF and place an oven rack in the lower part of the oven.
2. Transfer the filling to a 9-inch pie plate or a similar-sized baking dish.
3. If needed, roll out the leftover pie crust or puff pastry, and cut into pieces. Place the pieces, slightly overlapping, on top of the turkey filling. Brush the top with an egg wash.
4. Bake in the preheated oven for 40-45 minutes, until the pastry is light golden brown and the filling is completely heated through (reaching a temperature above 170ºF).
5. Remove the pot pie from the oven and transfer to a wire rack to cool for 5 minutes before serving.