Description
Potatoes au Gratin is a classic, creamy baked casserole featuring thinly sliced russet potatoes layered with onions and smothered in a rich cheddar cheese sauce. This comforting dish is perfect as a savory side or main course, showcasing tender potatoes and a golden, bubbly cheese topping.
Ingredients
Scale
Potatoes and Vegetables
- 6 medium russet potatoes, thinly sliced
- 1 medium onion, sliced
Cheese Sauce
- 3 tablespoons butter
- 3 tablespoons all-purpose flour
- 2 cups milk
- 1/2 teaspoon salt
- 1/2 teaspoon black pepper, to taste
- 1 ½ cups shredded Cheddar cheese
Instructions
- Preheat and Prepare Dish: Preheat your oven to 400℉ and grease a 9×13-inch baking dish thoroughly to prevent sticking and ensure even cooking.
- Layer Potatoes and Onions: Arrange half of the thinly sliced potatoes evenly on the bottom of the prepared casserole dish, then layer all the sliced onions. Follow with the remaining potato slices to create a layered base for the cheese sauce.
- Melt Butter and Make Roux: In a large skillet over medium heat, melt the butter. Stir in the flour and cook continuously for 1-2 minutes until it turns a golden color, forming a roux that will thicken the sauce.
- Add Milk and Season: While whisking constantly to prevent lumps, gradually add the milk, salt, and black pepper. Bring the mixture to a boil, then continue cooking for 1 minute until slightly thickened. Remove from heat and stir in the shredded cheddar cheese until melted and smooth.
- Assemble and Bake: Pour the rich cheese sauce over the layered potatoes and onions, ensuring even coverage. Cover the dish tightly with foil and bake for 50-60 minutes to cook the potatoes through. Then, remove the foil and bake an additional 15-20 minutes until the top is golden and bubbly, indicating a perfect gratin finish.
Notes
- For best results, use thinly sliced potatoes to ensure they cook evenly and become tender.
- You can substitute milk with half-and-half or cream for an even richer sauce.
- Feel free to add herbs like thyme or garlic powder to enhance flavor.
- Let the dish rest 10 minutes after baking before serving to allow it to set.
- Leftovers can be refrigerated and reheated for up to 3 days.
