Preheat to 375°F (190°C). Grease a 9×13-inch baking dish.
Cook the beef:
In a skillet over medium heat, cook the ground beef and chopped onion until beef is browned and onion is soft.
Drain excess fat and season with salt, pepper, and optional garlic powder or paprika.
Prepare sauce:
In a small bowl, mix the cream of mushroom soup with milk until smooth.
Layer the casserole:
Spread a thin layer of sliced potatoes at the bottom of the baking dish.
Add half of the cooked beef mixture on top.
Sprinkle with ½ cup shredded cheese.
Repeat with the remaining potatoes, beef, and another ½ cup cheese.
Pour the soup mixture evenly over the top.
Dot with butter if desired.
Bake:
Cover with foil and bake for 40 minutes.
Remove foil, sprinkle remaining cheese on top, and bake an additional 15–20 minutes, or until potatoes are tender and cheese is golden and bubbly.
Serve:
Let the casserole rest for 5 minutes before serving.
Tips:
For extra flavor, add sliced mushrooms, bell peppers, or a pinch of smoked paprika.
You can also use shredded hash browns instead of sliced potatoes for a quicker version.
Leftovers taste great reheated the next day!
If you want, I can give you a one-pot, super creamy version where everything cooks together without layering—it’s faster and just as cheesy. Want me to do that?
