Preheat your oven to 375°F (190°C) and grease a 9×13-inch baking dish with cooking spray or olive oil.

In a large skillet, heat the olive oil over medium heat. Add the ground beef and cook, breaking it apart with a spoon until the beef is browned and cooked through, about 5 to 7 minutes. Drain any excess fat if necessary.

Add the chopped onion and minced garlic to the skillet with the beef. Cook for another 3 to 4 minutes until the onion becomes soft and translucent.

Spread the cooked ground beef mixture evenly at the bottom of the prepared baking dish. Layer the thinly sliced potatoes on top.

Season the potatoes with salt, pepper, Italian seasoning, and paprika. Sprinkle shredded cheddar and grated Parmesan cheese over the beef.

Pour the beef broth or water around the edges of the casserole to keep the potatoes moist while baking. Optionally, drizzle with milk for extra creaminess.

Cover the casserole with aluminum foil and bake for 30 minutes. After this, remove the foil and continue baking for an additional 15 to 20 minutes, or until the potatoes are tender and the cheese is bubbly and golden.

Garnish with fresh parsley if desired and serve hot.