01 -
Preheat your oven to 175°C (350°F).
02 -
In a large skillet, cook the ground beef over medium heat until browned. Drain any excess fat.
03 -
(Optional) In the same skillet, add olive oil and sauté the chopped onions and minced garlic until they are soft and fragrant.
04 -
In a large mixing bowl, combine the cooked ground beef with the sautéed onions and garlic. Season with salt and pepper. In another bowl, mix the cream of mushroom soup with the milk until smooth.
05 -
In a greased 9x13 inch baking dish, layer half of the sliced potatoes then spread half of the beef mixture on top. Pour half of the soup mixture over the beef. Repeat the layers with the remaining potatoes, beef, and soup mixture.
06 -
Top the casserole with the shredded cheddar cheese.
07 -
Cover the baking dish with aluminum foil and bake in the preheated oven for 1 hour. After 1 hour, remove the foil and bake for an additional 15 minutes or until the potatoes are tender and the cheese is bubbly and golden brown.
08 -
Let the casserole rest for a few minutes before serving to allow it to set.