These Au Gratin Potatoes with Onions are deliciously creamy and cheesy. We really love the added flavor of the onion baked inside. This recipe serves 2 to 4 people when baked in an 8×8 baking dish, or could also be baked in 2 individual baking dishes. Plan ahead as it takes 1 ½ hours to bake, but it is so worth it!
Table of Contents
- Expert tips
- Recipe snapshot
- Reader comments
- Process shots for Au Gratin Potatoes for 2
- You may also enjoy

Need a main dish? Try this Tilapia Parm or these Individual Meatloaves.
Expert tips
Store cooked au gratin potatoes in an airtight container or tightly covered with foil in the refrigerator for 3–5 days. For best quality, reheat in the oven at 350°F- 375°F until heated through.
I do not recommend freezing au gratin potatoes. While freezing is possible for up to 1–3 months, the dairy-rich sauce may separate and become grainy upon thawing.
Recipe snapshot
Ingredients: russet potatoes, onion, pepper, butter, all-purpose flour, salt, milk, and shredded cheddar cheese.
Cuisine type: American French
Total time to make: 1 hour and 45 minutes
Reader comments
Denise – I made these potatoes tonight, and they were delicious! I used mini red potatoes and served them with mini meatloaves!
Dee – Zona, these are amazing!! Every single recipe of yours is fantastic!!
Process shots for Au Gratin Potatoes for 2




You may also enjoy
- Pork Chops and Potatoes
- Cheesy Mashed Potato Bake
- Stuffed Baked Sweet Potatoes
- Baked Potatoes in Toaster Oven

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Au Gratin Potatoes Recipe
Equipment
Ingredients
For the Potatoes:
- 2 medium russet potatoes (or 1 extra-large russet potato)
- 1 small onion
- Salt and pepper to taste
For the Sauce:
- 2 tablespoons butter
- 2 tablespoons all-purpose flour
- ¼ teaspoon salt
- 1 cup milk
- 1 cup shredded cheddar cheese
Instructions
- Preheat the oven to 400 degrees F.
- Spray an 8×8-inch baking dish with non-stick cooking spray.
For the Potatoes:
- On a cutting board, slice the potatoes into 1/4-inch slices and slice the onion into rings.
- Layer half of the onions into the bottom of the prepared dish.
- Add the potato slices.
- Top with the other half of the onions.
- Sprinkle the potatoes and onions with salt and pepper to taste.
For the Sauce:
- In a medium-size saucepan, melt the butter over medium heat.
- Whisk in the flour and salt, and stir constantly for one minute.
- Stir in the milk. Cook until mixture has thickened.
- Add in the cheese all at once, and continue stirring until melted, about 30 to 60 seconds.
- Pour the cheese sauce over the potatoes. Sprinkle on more salt and pepper if desired.
- Cover the dish with aluminum foil and place it on a baking sheet.
- Bake 90 minutes in the preheated oven.
- Remove the foil and broil for 2 – 5 minutes to brown the top, if desired.
Notes
- Store cooked au gratin potatoes in an airtight container or cover them tightly with foil. Keep them in the fridge for 3–5 days. For the best taste, reheat them in the oven at 350°F to 375°F until warm.
- I do not recommend freezing au gratin potatoes. While you can freeze them for 1–3 months, the creamy sauce may separate and become grainy when you thaw them.
Nutrition

Hi there, and a warm welcome! I’m Zona House, and my heart truly lies in the world of recipes.
I believe in simple, satisfying meals, so let’s make cooking enjoyable and delicious together! Eat, drink, and savor every moment!






Dee Dale
Monday 15th of April 2024
Zona, these are amazing!! Every single recipe of yours, on Pinterest, is fantastic!!
Zona House
Monday 15th of April 2024
Hi Dee Dale, thank you! I'm so glad you are enjoying them all :)
Denise
Sunday 24th of April 2022
I made these potatoes tonight and they were delicious! I used mini red potatoes and served them with mini meatloafs!
Nancy Dunn
Friday 1st of January 2021
I made this recipe for myself and cut the ingredients in half. It was very easy to make and tasted good. Would recommend and will make again.
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