Creamy au Gratin Potatoes
Ingredients
- 4 medium-sized russet potatoes thinly sliced
- 1 medium-sized onion sliced into rings
- Salt and black pepper to taste
- 3 tablespoons butter
- 3 tablespoons all-purpose flour
- ½ teaspoon salt
- 2 cups milk
- 1 ½ cups shredded Cheddar cheese
Instructions
- Preheat the oven to 400 degrees Fahrenheit (200 degrees Celsius). Butter a 1-quart casserole dish.
- In the prepared casserole dish, layer 1/2 of the sliced potatoes on the bottom. Season with salt and pepper. Layer onion slices over the potatoes, then top with the remaining potatoes. Season again with salt and pepper.
- Melt the butter in a medium-sized saucepan over medium heat. Gradually whisk in the flour and salt, and cook while whisking constantly until the raw flour flavor has cooked off, about 1 minute.
- Gradually add milk, about 1/4 cup at a time, whisking well after each addition to incorporate; this gradual addition and whisking of milk will help avoid lumps in your sauce.
- Cook, whisking constantly, until the mixture has thickened, which will take about 3 to 5 minutes. Stir in the cheese all at once; continue stirring until melted, which will take around 30 to 60 seconds.
- Pour the cheese sauce over the potatoes, and cover the dish with aluminum foil.
- Bake in the preheated oven until the potatoes are tender and the sauce is bubbly, which will take around 1 1/2 hours.
- Enjoy your delicious creamy au gratin potatoes!
Notes
For optimal results, ensure that the potatoes are sliced into 1/4-inch (or even thinner) slices. A mandolin would come in handy if you have one available.