1. Prepare the ground beef mixture:

Heat a large skillet over medium heat. Add the ground beef and cook until browned, breaking it into crumbles with a spatula. Add the diced onion and garlic, cooking for another 2-3 minutes until the onion softens. Season the mixture with salt, black pepper, and smoked paprika. Once the beef is fully cooked, drain any excess grease and set aside.

2. Mix the creamy sauce:

In a small bowl, combine the cream of mushroom soup and milk. Whisk until smooth. This sauce will keep the casserole moist and add a creamy texture.

3. Prepare the potatoes:

Peel the potatoes and slice them thinly (about 1/8 inch thick) for even cooking. Use a mandoline slicer for consistent slices if you have one.

4. Assemble the casserole:

Grease a 9×13-inch baking dish with olive oil. Begin layering the ingredients:

• Start with a layer of sliced potatoes, slightly overlapping them.
• Add half of the cooked ground beef mixture on top of the potatoes.
• Pour half of the creamy sauce over the beef.
• Sprinkle 3/4 cup of shredded cheese evenly over the sauce.
• Repeat the layers (potatoes, beef, sauce, and cheese) with the remaining ingredients.

5. Bake the casserole:

Preheat your oven to 375°F (190°C). Cover the baking dish with aluminum foil and bake for 35 minutes. Then, remove the foil and bake for an additional 15 minutes to allow the cheese to brown and the edges to crisp up.

6. Let it rest and serve:

Once baked, let the casserole rest for 5-10 minutes to set. Garnish with chopped parsley or green onions for a pop of color before serving.