1. Preheat the oven to 400°F (200°C) and spray a 9×13-inch casserole dish with nonstick cooking spray.

2. In a large bowl, toss the sliced potatoes with melted butter and 1/2 teaspoon salt until well coated.

3. Layer the potatoes across the bottom and up the sides of the prepared dish, overlapping slightly.

4. Bake the potatoes in the oven for 20–30 minutes, or until fork-tender.

5. Meanwhile, in a skillet over medium-high heat, cook the ground beef until browned and crumbly, about 5–7 minutes. Drain excess grease.

6. In a large bowl, combine the cooked beef, cream of mushroom soup, 3/4 cup Cheddar cheese, and milk. Season with salt and pepper to taste.

7. Remove the casserole dish from the oven and pour the beef mixture over the baked potatoes.

8. Return the dish to the oven and bake for another 15 minutes until heated through.

9. Sprinkle the remaining 3/4 cup of Cheddar cheese over the top and bake for an additional 4–5 minutes until the cheese is melted and bubbly.

10. Let sit for 5 minutes before serving. Garnish with chopped parsley if desired.