In a large skillet, heat over medium-high heat and add 1 pound of ground beef and 0.5 pound of mild Italian sausage. Cook until browned, around 7-10 minutes, ensuring to drain any excess grease.

Add 0.5 cup of finely diced yellow onion and 2 cloves of minced garlic, stirring until the onion softens, about 5-7 minutes.

Stir in 1 teaspoon of dried Italian seasoning, 0.5 teaspoon of salt, and 0.25 teaspoon of black pepper, cooking for another minute.

Remove from heat and mix in 0.25 cup of marinara sauce and half of the pepperoni, letting it cool slightly.

Preheat your oven to 375°F (190°C). Take one pie crust and carefully press it into a deep-dish pie plate.

Spread 1 cup of shredded mozzarella cheese on the bottom, followed by all of the shredded provolone cheese.

Layer the cooled meat mixture over the cheese, and then sprinkle the remaining mozzarella cheese on top.

Place the second pie crust over the filling, crimp the edges together, and cut several slits for steam to escape.

Bake for 30 minutes. After this time, spread the remaining marinara sauce over the top, arranging the remaining pepperoni slices.

Return the pie to the oven for an additional 15-20 minutes, or until the crust is golden brown and the filling is bubbling and hot.

Once baked, allow the pie to rest for 10-15 minutes before slicing and serving warm.