“Nothing beats coming home to a warm, home-cooked meal! One bite of this incredible dish my husband made, and all the stress of the day just completely melted away.”

Step 1: Prepare the Oven

Preheat the oven to 350°F (175°C). Lightly grease a 9×13-inch baking dish with butter or nonstick cooking spray.

Step 2: Cook the Onions

In a large skillet, melt 2 tablespoons of butter over medium heat. Add the sliced onions and cook for 10–15 minutes, stirring occasionally, until they are soft, lightly caramelized, and golden.

Step 3: Make the Cheese Sauce

Add the remaining 2 tablespoons of butter to the skillet. Once melted, stir in the flour and cook for 1 minute, stirring constantly. Slowly whisk in the milk until smooth. Simmer over medium-low heat for 5–7 minutes, stirring often, until the sauce thickens.

Step 4: Season the Sauce

Mix in the salt, black pepper, and garlic powder, if using. Remove the skillet from the heat and taste, adjusting the seasoning if desired.

Step 5: Assemble the Casserole

Arrange half of the sliced potatoes in an even layer in the prepared baking dish. Top with half of the cooked onions, 1 cup of the shredded cheddar cheese, and half of the cream sauce. Repeat with the remaining potatoes, onions, cheese, and sauce.

Step 6: Bake Covered

Cover the baking dish tightly with aluminum foil. Bake for 45 minutes, allowing the potatoes to become tender.

Step 7: Brown the Top

Remove the foil and continue baking for 15–20 minutes, or until the cheese is bubbling and golden brown and the potatoes are easily pierced with a fork.

Step 8: Let It Rest

Remove the casserole from the oven and let it rest for 10–15 minutes before serving. This allows the sauce to thicken slightly, making it easier to serve neat portions.

Tip

Allowing the casserole to rest before serving is an important step. As it cools slightly, the creamy sauce sets and thickens, helping each serving hold together while keeping the potatoes rich, tender, and flavorful.