Preheat oven to 375°F (190°C).
Lightly grease a 9x13-inch baking dish with olive oil.
Brown ground beef in a skillet over medium heat and drain excess fat.
Season beef with garlic powder, paprika, salt, and black pepper.
Layer half of the sliced potatoes in the baking dish.
Spread half of the cooked beef over the potatoes.
Add sliced onions evenly on top.
Repeat layers with remaining potatoes and beef.
In a bowl, whisk cream of mushroom soup and milk.
Pour soup mixture evenly over the layered ingredients.
Cover with foil and bake for 45 minutes.
Remove foil, sprinkle cheddar cheese on top, and bake uncovered for 15 more minutes until cheese melts and potatoes are tender.