First, preheat your oven to 350 degrees Fahrenheit (175 degrees Celsius).
2. Cook the chopped onion and ground beef in a big pan over medium heat until the onion is soft and the meat is browned. Remove any surplus of fat.
3. Melt some butter in a 9×13 inch baking dish. Half of the thinly sliced potatoes should go on the bottom.
After the steak and onions are browned, spread them out equally over the potatoes.
Cream of mushroom soup, milk, salt, and pepper should be combined in a small dish. 5. Toss the potatoes and meat with half of the mixture.
6. Top with a quarter cup of crumbled cheddar cheese.
7. Once the cheese has been layered, add the remaining potatoes. Finally, pour the remaining soup liquid on top.
8. Bake for 30 minutes with the foil covering the dish.
9 After ten to fifteen minutes, take the foil off and top with the remaining cup of cheese. Bake until the potatoes are soft and the cheese is brown and bubbling.
10. After a few minutes of cooling, serve the casserole so the layers can solidify.
Changes and Hints

Garlic powder or paprika, when mixed with meat, may offer a little more flavor. You may use cream of chicken instead of mushroom soup if you like that flavor. To spice things up and add some additional vegetables, try layering green beans or peas between the potatoes and steak. Finally, in the last baking step, you may add additional bread crumbs combined with melted butter if you want a little crispier top.

First, preheat your oven to 350 degrees Fahrenheit (175 degrees Celsius).
2. Cook the chopped onion and ground beef in a big pan over medium heat until the onion is soft and the meat is browned. Remove any surplus of fat.
3. Melt some butter in a 9×13 inch baking dish. Half of the thinly sliced potatoes should go on the bottom.
After the steak and onions are browned, spread them out equally over the potatoes.
Cream of mushroom soup, milk, salt, and pepper should be combined in a small dish. 5. Toss the potatoes and meat with half of the mixture.
6. Top with a quarter cup of crumbled cheddar cheese.
7. Once the cheese has been layered, add the remaining potatoes. Finally, pour the remaining soup liquid on top.
8. Bake for 30 minutes with the foil covering the dish.
9 After ten to fifteen minutes, take the foil off and top with the remaining cup of cheese. Bake until the potatoes are soft and the cheese is brown and bubbling.
10. After a few minutes of cooling, serve the casserole so the layers can solidify.
Changes and Hints

Garlic powder or paprika, when mixed with meat, may offer a little more flavor. You may use cream of chicken instead of mushroom soup if you like that flavor. To spice things up and add some additional vegetables, try layering green beans or peas between the potatoes and steak. Finally, in the last baking step, you may add additional bread crumbs combined with melted butter if you want a little crispier top.