Preheat oven to 350 degrees F. Coat a 2 ½-quart round baking dish with cooking spray and set aside. In a large skillet, heat the olive oil over medium heat. Add the carrots, peas, onions, salt and pepper. Cook, stirring occasionally, until veggies are soft and the onion is fragrant, 4 to 5 minutes.
Add the chicken, chicken broth, soup, milk and flour (if using). Mix well and cook over medium-low heat for an additional 5 minutes.
Pour the contents of the skillet into the prepared baking dish. Cover with the pie crust, letting the edges hang over the sides of the dish. Using a sharp knife, cut a few slits into the dough. Place baking dish on a baking sheet and bake in the preheated oven for 40 minutes, or until crust is lightly browned. Let cool for 10 minutes. Cut pizza-style and serve warm!