01 -
Preheat the oven to 375°F. Grease a 9x13 inch baking dish with butter.
02 -
Cook the ground beef and onion in a large skillet over medium-high heat for 7-9 minutes, breaking up the meat, until browned and no pink remains. Drain excess fat.
03 -
Stir in the garlic, Worcestershire sauce, 1/2 teaspoon salt, and black pepper. Cook for 30 seconds, then remove from the heat.
04 -
Whisk the cream of mushroom soup, milk, garlic powder, and remaining 1/2 teaspoon salt in a bowl until smooth.
05 -
Arrange half the potato slices in the prepared dish. Spread the beef mixture over them, then add the remaining potatoes. Pour the sauce evenly over the top.
06 -
Cover the dish tightly with foil and bake for 55-65 minutes, until the potatoes are almost tender when pierced with a knife.
07 -
Remove the foil, sprinkle the cheddar over the top, and bake uncovered for 12-15 minutes, until melted and bubbling. Rest for 10 minutes before serving with parsley or chives.