Preheat the oven to 350*
Spray a 9×13 baking dish with a non stick cooking spray
In a large skillet, add the onion and ground beef and cook until the meat is done
Slice the potatoes to about ¼” slices
Add one layer of potatoes to the bottom of the baking pan
Sprinkle with salt and pepper
Top with approximately ⅓ of the meat mixture and spread evenly over the potatoes
Sprinkle with ⅓ of the shredded cheese
Repeat this two more times in layers
The last layer should be the remaining cheese
In a bowl, combine the Cheddar cheese soup mix, the milk and the evaporated milk, with optional salt and pepper if desired
Pour the soup mix over the top of the potatoes and beef mixture
Cover the baking pan tightly with aluminum foil and place in the oven
Bake for one hour
Remove the foil and bake for an additional 15 minutes to get a golden topping on the cheese.
If the potatoes are thicker, you will need to bake the dish longer

Enjoy