Preheat the oven to 425°F (220°C).
In a skillet over medium heat, cook the chopped onion and ground beef until browned. Drain excess fat.
Stir in pizza sauce, salt, pepper, and Italian seasoning; mix well and let cool slightly.
Roll out one pie crust and place it in a pie dish.
Layer the meat mixture on top, followed by the cheese and desired toppings.
Cover with the second pie crust, sealing the edges by crimping.
Cut slits in the top crust to allow steam to escape.
Bake for 25-30 minutes or until the crust is golden brown.
Let it cool slightly before serving.