Heat the oven before using it.
Preheat your oven to 350°F (175°C). This helps the dish cook evenly and makes sure the ingredients blend together nicely.
Get the potatoes ready.
Clean, peel, and cut the potatoes into thin, round slices that are about 1/8-inch thick. It’s important to be consistent so that the potatoes cook evenly. Put them to the side.
Prepare the minced meat.
In a big frying pan on medium heat, cook the ground beef until it’s no longer pink. Cut it into small pieces while it cooks, and put in the chopped onions. Cook for 2-3 more minutes until the onions are soft. Remove extra fat and add salt, pepper, and any other seasonings you like.
Make the creamy sauce.
In a bowl, combine the can of mushroom soup with milk until it’s well mixed. This blend will help the casserole stay moist and creamy while it cooks in the oven.
Place the ingredients one on top of the other.
Lightly coat a 9×13-inch baking dish with cooking spray or butter. Begin by placing half of the potato slices at the bottom of the dish. Put a little salt and pepper on the potatoes. Put half of the cooked ground beef on the potatoes, then add half of the soup. Do another layer with more potatoes, ground beef, and soup.
Put cheese on top.
Put the grated cheddar cheese evenly on top. This will make a tasty golden crust with bubbles when it bakes.
Make the casserole.
