First Step: Preparing the Ingredients: Start by preheating your oven to 400–425°F (204–218°C). Chop the yellow onion and green bell pepper into small pieces. Open and drain the canned black olives and mushrooms. Measure out your Italian seasoning, garlic powder, salt, and any pizza and pasta seasoning blends you plan to use. Prepare a 9×13 inch baking dish by lightly greasing it to prevent sticking.

Second Step: Cooking the Meat and Vegetables: Heat 1 tablespoon of olive oil in a large skillet over medium-high heat. Add the ground beef and Italian pork sausage to the pan. Season the meat mixture with 1 teaspoon salt, 2 teaspoons Italian seasoning, and ½ teaspoon garlic powder. Break up the meat with a spatula and cook until it’s no longer pink, about 7-8 minutes. Drain any excess grease to prevent a soggy casserole.

Next, stir in the chopped onion, green bell pepper, sliced olives, mushrooms, and half the pepperoni slices. If you’re using the optional pizza and pasta seasoning blend, add it now. Pour in the marinara or pizza sauce and stir well. Allow the mixture to simmer briefly for 3-5 minutes to combine flavors, then remove the skillet from heat.

Third Step: Assembling the Casserole: Spread the cooked meat and vegetable mixture evenly across the bottom of your prepared baking dish. Open the bag of frozen tater tots and arrange them in a single layer on top of the meat mixture, covering it completely. This forms the crispy pizza base of the casserole.

Fourth Step: Baking the Base: Place the casserole in the preheated oven. Bake uncovered for 30–40 minutes, or until the tater tots turn golden brown and crispy. This step is crucial to achieve that satisfying crunch that defines the dish. Avoid covering the casserole so the tater tots don’t steam and become soggy.

Final Step: Adding Cheese and Toppings: Remove the casserole from the oven carefully. Evenly sprinkle 2 cups of shredded mozzarella cheese over the crispy tater tots. Arrange the remaining pepperoni slices on top of the cheese. Optionally, sprinkle a pinch of Italian seasoning for an extra herbaceous aroma.

Return the casserole to the oven and bake for an additional 5–10 minutes, until the cheese melts completely and bubbles with a light golden color.

Let the casserole cool for about 5 minutes before serving. This resting time helps it set, making it easier to cut into portions.