Step 1: Prep the Potatoes

• Thinly slice your Yukon gold potatoes (about ⅛-inch thick). Immediately submerge them in cold water to prevent browning while you prepare the other ingredients.

Step 2: Preheat and Prep the Dish

• Preheat your oven to 350°F (177°C). Lightly grease a 9×13-inch baking dish and set it aside.

Step 3: Brown the Beef

• In a large saucepan or Dutch oven, cook the ground beef with diced onions and minced garlic over medium-high heat. Stir frequently to break up the meat and ensure even browning. Once cooked through, drain off any excess grease.

Step 4: Mix the Sauce

• In a bowl, combine the cream of mushroom soup, half and half, onion powder, salt, and black pepper. Whisk until smooth.

Step 5: Layer the Casserole

Drain the potato slices and start layering:

• Add ⅓ of the potatoes to the bottom of the prepared baking dish.
• Top with ⅓ of the ground beef mixture.
• Sprinkle with ¾ cup of shredded cheese.
• Drizzle with ⅓ of the cream sauce.
• Repeat the process two more times, using up the remaining ingredients. For the top layer, use 1½ cups of cheese to cover the casserole completely.

Step 6: Bake

• Cover the dish tightly with foil and bake for 1 hour and 10 minutes. Then, remove the foil and bake uncovered for an additional 20 minutes until the cheese is golden and bubbling.

Step 7: Rest and Serve

• Let the casserole rest for at least 15 minutes before slicing. This allows the layers to settle and makes serving much easier.