Preheat your oven to 350°F (175°C).
In a skillet, cook the ground beef and onion over medium heat until browned.
Drain excess fat and season with garlic powder, paprika, salt, and pepper.
In a large bowl, mix cream of mushroom soup and milk until smooth.
Layer half of the sliced potatoes in a greased casserole dish.
Spread half of the cooked beef mixture over the potatoes.
Pour half of the soup mixture over the layers.
Repeat the layers with the remaining potatoes, beef, and soup mixture.
Top with shredded cheese.
Bake in the preheated oven for 45 minutes or until the potatoes are tender.