In a large skillet over medium-high heat, cook the ground beef, onion, and garlic until the beef is browned and the onion is tender, about 8 minutes. Drain off any excess fat.
Stir in the spinach, Italian seasoning, salt, and pepper. Cook for 2 minutes, stirring frequently.
Remove from heat and stir in the mozzarella, Parmesan, and ricotta cheeses.
Roll out one of the pie crusts and place in a 9-inch pie plate. Pour the meat and spinach mixture into the pie crust.
Roll out the remaining pie crust and place on top of the filling. Crimp the edges together to seal.
Cut a few slits in the top of the crust to allow steam to escape.
Bake for 25-30 minutes, until the crust is golden brown.
Allow to cool for 10 minutes before serving.
Interesting Facts
This Italian Meat and Spinach Pie is a great way to use up leftover cooked ground beef.
The dish can also be made ahead of time and frozen for up to three months.
Feel free to experiment with different cheeses or herbs to customize the flavor.