Preheat the oven to 375°F. Grease a 9×13-inch baking dish.
Heat olive oil in a skillet over medium-high heat. Cook ground beef and onion for 7 to 9 minutes until browned. Drain excess grease.
Stir in garlic, paprika, garlic powder, black pepper, and ½ teaspoon salt. Cook for 1 minute.
In a bowl, whisk together cream of mushroom soup, milk, sour cream, and Worcestershire sauce.
Toss the sliced potatoes with the remaining ½ teaspoon salt.
Layer half the potatoes, ground beef, and sauce in the baking dish. Repeat the layers.
Cover tightly with foil and bake for 60 minutes, or until the potatoes are fork-tender.
Remove the foil, sprinkle cheddar cheese over the top, and bake uncovered for 10 to 15 minutes until melted and bubbly.
Let rest for 10 minutes. Garnish with parsley and serve warm.