Creamy au Gratin Potatoes

Recipe View Preheat the oven to 400 degrees F (200 degrees C). Generously butter a 2-quart casserole dish. (5 minutes)

Recipe View Layer half of the potato slices in the prepared dish, overlapping slightly. Season with salt and pepper. (5 minutes)

Recipe View Arrange the onion rings evenly over the potatoes, then top with the remaining potato slices. Season again with salt and pepper. (5 minutes)

Recipe View In a medium saucepan, melt the butter over medium heat. Whisk in the flour and sea salt until smooth. Cook, whisking constantly, for about 1 minute to cook out the raw flour taste. (2 minutes)

Recipe View Gradually whisk in the milk, about 1/4 cup at a time, ensuring each addition is fully incorporated before adding more. This will prevent lumps from forming in the sauce. (5 minutes)

Recipe View Continue cooking and whisking until the sauce has thickened to a smooth, creamy consistency, about 3 to 5 minutes. (5 minutes)

Recipe View Remove the saucepan from the heat and stir in the shredded Cheddar cheese all at once. Continue stirring until the cheese is completely melted and the sauce is smooth and glossy. (2 minutes)

Recipe View Pour the cheese sauce evenly over the potatoes, ensuring they are fully coated. Cover the dish tightly with aluminum foil. (2 minutes)

Recipe View Bake in the preheated oven for 1 hour. Remove the foil and continue baking for another 30 minutes, or until the potatoes are tender and the top is golden brown and bubbly. (90 minutes)

Recipe View Let the dish rest for 10 minutes before serving. (10 minutes)