Place the ground beef in a medium skillet over medium heat.
Cook the beef until brown, then drain the fat.
In a medium bowl, add the cream of mushroom soup, onion, milk, salt, and pepper.
Using a spoon, mix the ingredients until combined.
Place a layer of potatoes in an 11x7 inch baking dish.
Add a layer of the soup mixture on top of the potatoes.
Add a layer of cooked ground beef on top of the soup mixture.
Repeat the layers until all ingredients are used.
Place the baking dish in the oven and bake for 1 to 1½ hours, or until the potatoes are tender.
Remove the dish from the oven and sprinkle the Cheddar cheese on top.
Return the dish to the oven and bake until the cheese melts.
Notes
Tips and Tricks
Slice Potatoes Evenly - Use a sharp knife or a mandoline slicer to cut the potatoes into thin, even slices. This helps them cook at the same rate and become tender throughout.Season the Beef Well - Don't skip seasoning the ground beef before browning. Salt, pepper, and garlic powder add flavor that spreads through the entire dish.Drain the Fat - After browning the beef, drain off the excess fat. This keeps the casserole from becoming greasy and helps the layers stay distinct.Cover with Foil - If the top starts to brown too quickly, cover the baking dish with aluminum foil. Remove it during the last 15 minutes so the cheese can melt and turn golden.Let It Rest - Allow the casserole to sit for 5 to 10 minutes after baking. This helps the layers set and makes it easier to serve.Check Potato Tenderness - Insert a fork into the potatoes to check if they're done. They should slide in easily without resistance.
Storing and Reheating
Store in Refrigerator - Place leftovers in an airtight container and refrigerate for up to 4 days. You can also cover the baking dish tightly with plastic wrap or aluminum foil.Freeze for Later - Wrap individual portions in plastic wrap, then place them in a freezer-safe container or bag. Freeze for up to 3 months. Thaw in the refrigerator overnight before reheating.Reheat in Oven - Preheat the oven to 350°F. Place a serving in an oven-safe dish, cover with foil, and heat for 15 to 20 minutes until warmed through.Reheat in Microwave - Place a serving on a microwave-safe plate. Cover with a damp paper towel and heat on high for 1 to 2 minutes, stirring halfway through.