Set your oven to preheat at 350°F.
In a skillet over medium-high heat, cook the ground beef along with the chopped onion and minced garlic until the meat is browned through, then drain off the excess fat.
Hint: For added texture, consider stirring in green bell peppers and corn while cooking the beef mixture.
Prepare an 11×8 inch baking dish by spraying it with nonstick spray, then layer the sliced potatoes evenly at the bottom.
Combine the condensed mushroom soup, milk, salt, and pepper in a bowl and pour this sauce evenly over the potatoes.
Spread the cooked ground beef mixture on top, covering the potatoes and sauce.
Cover the dish with foil and bake for about an hour until the potatoes are tender.
Take off the foil, sprinkle the shredded cheddar cheese on top, and return to the oven for another 10 minutes until the cheese melts nicely.
Let the casserole sit for a few minutes to firm up before serving.
Store leftovers in an airtight container in the fridge for up to 3-4 days.
