Preheat the oven to 350°F (175°C).
In a large skillet, heat the olive oil over medium heat. Add the chopped onion and minced garlic, and sauté until the onion is translucent, about 3-4 minutes.
Add the ground beef to the skillet and cook until browned, breaking it apart with a spoon. Drain any excess fat.
In a mixing bowl, combine the cream of mushroom soup, milk, salt, pepper, and paprika. Stir until smooth.
In a greased casserole dish, layer half of the sliced potatoes at the bottom. Season lightly with salt and pepper.
Spread half of the cooked ground beef mixture over the potatoes, followed by half of the soup mixture.
Repeat the layers with the remaining potatoes, ground beef, and soup mixture, finishing with a layer of the shredded cheddar cheese on top.
Cover the casserole dish with aluminum foil and bake in the preheated oven for 40 minutes.
Remove the foil and bake for an additional 10 minutes, or until the cheese is bubbly and golden brown.
Let the casserole cool for a few minutes before serving.