This Easy Au Gratin Potato recipe is the perfect comfort-food side dish, especially during the holidays. Made with canned potatoes, it is simple, reliable, and ideal for both beginners and experienced home cooks. Using canned potatoes means less prep time and a consistently tender texture, while the rich, creamy cheese sauce delivers classic au gratin flavor.
This recipe is intentionally a bit more saucy than traditional versions because cooked potatoes do not absorb sauce the same way fresh potatoes do. If you love extra cheese sauce to spoon—or drag other parts of your plate through—this recipe is for you. However, if you prefer a firmer, more set-up au gratin, easy adjustments are included to thicken the sauce.
Don’t be intimidated by the cheese sauce. Even if it’s not perfect, it will still taste delicious. One of the best parts of this recipe is that it can be baked a day ahead and reheated just before serving, making it perfect for holidays or gatherings.
Ingredients
2 (15 oz) cans sliced potatoes, drained well
3 tablespoons butter
3 tablespoons all-purpose flour
2 cups whole milk (or half-and-half for extra richness)
1½ cups shredded cheddar cheese
½ cup shredded mozzarella or Gruyère (optional, for extra creaminess)
1 teaspoon salt
½ teaspoon black pepper
½ teaspoon garlic powder
¼ teaspoon paprika (optional)
Method of Preparation
Preheat the Oven
Preheat your oven to 375°F (190°C). Lightly grease a baking dish and set it aside.
Prepare the Cheese Sauce
In a saucepan over medium heat, melt the butter. Whisk in the flour and cook for about 1 minute, stirring constantly, to remove the raw flour taste.
Add the Milk
Slowly whisk in the milk, continuing to stir to avoid lumps. Cook until the sauce begins to thicken slightly.
Add Cheese and Seasonings
Lower the heat and add the shredded cheeses, salt, pepper, garlic powder, and paprika. Stir until the cheese is fully melted and the sauce is smooth.
For a thicker sauce, allow it to cook a bit longer or add an extra tablespoon of cheese.
Assemble the Dish
Layer the drained canned potatoes evenly in the prepared baking dish. Pour the cheese sauce over the potatoes, making sure they are well coated.
Bake
Cover loosely with foil and bake for 25 minutes. Remove the foil and bake an additional 10–15 minutes until bubbly and lightly golden on top.
Rest and Serve
Let the dish rest for 10 minutes before serving to allow the sauce to settle slightly.
Make-Ahead & Reheating Instructions
Make Ahead: Bake the dish completely, let it cool, cover tightly, and refrigerate for up to 24 hours.
Reheat: Cover with foil and reheat at 350°F (175°C) until warmed through.