Preheat the oven to 375°F (190°C).

Thinly slice the potatoes to ¼-inch thickness and set aside.

In a skillet, heat olive oil, then sauté onions and garlic until fragrant. Add ground beef and cook until browned. Season with Italian seasoning, paprika, salt, and pepper.

Grease a baking dish, layer half of the sliced potatoes, followed by half of the beef mixture and half of the cheddar cheese. Repeat layers and pour beef broth (and milk, if using) on top.

Cover with foil and bake for 35-40 minutes until potatoes are tender.

Remove foil, sprinkle grated parmesan cheese, and return to the oven uncovered for an additional 10 minutes until cheese is bubbly and golden brown.

Let the casserole rest for 5 minutes, then garnish with parsley before serving.