Step 1: Prepare the Potatoes

Peel and Slice Potatoes: Start by peeling the potatoes and slicing them thinly. This will help them cook evenly and quickly in the oven.
Pre-cook the Potatoes: To ensure the potatoes are tender, you can pre-cook them slightly. Place the sliced potatoes in a pot of boiling water for about 5 minutes. Drain and set aside.
Step 2: Prepare the Ground Beef Mixture

Cook the Ground Beef: In a large skillet, heat 2 tablespoons of olive oil over medium heat. Add the chopped onion and minced garlic, and sauté until the onion becomes translucent.
Add Ground Beef: Add the ground beef to the skillet and cook until it’s browned. Break it apart with a spatula as it cooks to ensure even browning.
Season the Beef: Season the beef with salt, black pepper, and paprika. Add the chopped parsley and mix well.
Add Tomatoes and Sauce: Stir in the can of diced tomatoes and tomato sauce. Let the mixture simmer for about 5 minutes to allow the flavors to meld together.
Step 3: Assemble the Casserole

Layer the Potatoes: In a large baking dish, create an even layer of the pre-cooked potato slices at the bottom.
Add Beef Mixture: Spoon half of the ground beef mixture over the layer of potatoes, spreading it out evenly.
Repeat Layers: Add another layer of potato slices, followed by the remaining ground beef mixture. Finish with a final layer of potato slices on top.
Top with Cheese: Sprinkle the shredded mozzarella cheese and grated Parmesan cheese evenly over the top layer of potatoes.
Step 4: Bake the Casserole

Preheat Oven: Preheat your oven to 375°F (190°C).
Bake: Cover the baking dish with aluminum foil and bake in the preheated oven for 30 minutes. This will help the potatoes cook through without the cheese burning.
Remove Foil: After 30 minutes, remove the foil and bake for an additional 15-20 minutes, or until the cheese is melted and golden brown, and the potatoes are tender when pierced with a fork.