This Cheesy Diced Potato Casserole is a comforting one-pan potato side dish consisting of creamy soft diced potatoes with melted mozzarella, sweet red onions, aromatics, and warm spices.
Enjoy this potato au gratin casserole as a tasty side dish to any midweek family meal or for special occasions and holidays!
❤️ Why I love this recipe
- It’s a classic potato side dish that never goes out of style - perfect for a midweek family meal or to serve with holiday meals.
- Creates minimal mess or fuss by cooking and baking everyone in one skillet!
- Easily adapt this potato au gratin casserole by making simple ingredient swaps or add-ins.
This cheesy potatoes recipe is an incredibly comforting and easy side dish that can complement almost any meal!
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Note: The full list of this diced potato gratin recipe ingredients with their amounts and options are listed in the recipe card below.
- Potatoes -- for this dish I used russet potatoes.
- Unsalted butter -- if you use salted you'll have to decrease the salt in the recipe.
- Onion -- I used a red onion but you may use white or yellow instead.
- All-purpose flour -- this will help thicken the liquid for a creamy sauce.
- Chicken stock -- this is part of the cheesy sauce.
- Heavy cream -- the base of the creamy au gratin sauce.
- Kosher salt - seasoning.
- Black pepper - spicing the potatoes and sauce.
- Nutmeg - a classic seasoning in a white sauce that adds a touch of warmth.
- Basil -- gives the sauce piquancy, aroma and taste.
- Garlic powder -- adds a light garlicky touch to the smooth creamy sauce.
- Mozzarella cheese -- cheese is a necessary ingredient in an au gratin recipe.
Note: This is an overview of the instructions. The full instructions are in the recipe card below.
- Preheat the oven and add the diced potatoes in an even layer to a greased baking dish.
- Make the creamy sauce and pour it over the potatoes.
- Make sure that all potatoes are well coated.
- Sprinkle the shredded cheese over the top.
- Cover the baking dish with aluminum foil and bake for 28-30 minutes. The foil can be removed in the last 10 minutes of baking to achieve a golden top.
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You’ll need the following items to make this recipe successfully.
These are the questions we are most frequently asked about making an au gratin dish with diced potatoes.
Russet potatoes or Yukon Gold potatoes are great for gratin potatoes as they have a high scratch content. The starch helps the potatoes hold shape while being buttery and soft.
Gratin potatoes consist of thinly sliced potatoes cooked in a creamy sauce and topped with shredded cheese or breadcrumbs.
The potatoes won’t soften if sliced too thick, if there is insufficient liquid in the recipe, if the cooking time is inadequate, if the oven temperature is not set to the correct temperature, or if the wrong type of potato is used.
This depends on personal preference. Always select a cheese that melts well. Cheddar, gruyere, parmesan, Swiss cheese, and mozzarella cheese are good options for this type of dish.
- Whisk the roux into the cheesy potatoes mixture to prevent the mixture from burning on the bottom of the skillet. The heat on the stovetop should not be made too high.
- Dicing the potatoes into uniform-sized cubes will help to cook the potatoes evenly.
- Use a cast iron skillet to make this diced potatoes casserole or a thick pan that can withstand the heat of the oven.
- Always shred cheese from a block of cheese for the best flavor and melting.
- This easy side dish has been made with Russet potatoes, but Idaho white potatoes, Yukon Gold, or yellow potatoes can also be used.
- Yellow onions or shallots can replace red onions.
- Use any cheese you enjoy the most, such as mozzarella or gouda.
- Add other vegetables to this potato casserole, such as peas, for extra nutritional value.
- Add chopped bacon to this potato au gratin casserole for a meaty and salty flavor.
Leftover cheesy potatoes can be stored in an airtight container in the fridge for 3-4 days or in the freezer for 2-3 months.
Reheat the leftover potato casserole in the oven at 350F, covered with aluminum foil, until heated throughout.
📗 Related Recipes
- Skillet Fried Italian Herbed Potatoes - An easy one-pan potato side dish with Italian seasonings.
- Potatoes Au Gratin With Gruyere Cheese - The perfect holiday side dish that everyone loves!
- Sweet Potato Casserole With Bacon - A double-baked potato casserole consisting of sweet potatoes, bacon, green onion, Double baked mashed sweet potatoes with bacon, green onion, smoky chipotle powder, and topped with buttery breadcrumbs.
🍽 Serve with
Enjoy these creamy potatoes with grilled meats, roasted chicken, steak, or your favorite fish. This potato casserole is an excellent side dish for holiday meals too!
Sprinkle freshly chopped parsley or basil over the potato casserole before serving.
📞 Chiacchierata (chat)
Every holiday occasion always included my Mamma's scalloped potatoes. How can you refuse delicious potatoes bathed in a rich creamy onion sauce. But when Mamma passed the holiday cooking baton onto me, I decided to shake things up a little bit.
Instead of scalloped potatoes, I went one better - potatoes bathed in a creamy oniony cheese sauce. So every year we make Potatoes Au Gratin. These are potatoes that include onions and cream, but also bacon and gruyere cheese. They take a bit of work but they're totally worth making for the holidays or special occasion.
But we love the delicious au gratin side. So whenever we get the hankering for potatoes that include something oniony, cheesy, and creamy, we make this potato gratin recipe.
Tutti a tavolo, è pronto!
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📝 Recipe Card
Cheesy Creamed Potato Casserole is a one-pan potato side dish consisting of soft diced potatoes cooked in a creamy sauce with red onions, melted mozzarella, warm spices, and aromatics.
If you love this recipe please give it 5 stars ⭐️⭐️⭐️⭐️⭐️.
Cheesy Diced Potato Casserole
- 4 cups of diced potatoes I used russet potatoes about 6 to 8 small potatoes
- 2 tablespoons of butter
- ¼ cup of minced red onion
- 2 tablespoons of flour
- ½ cup of chicken stock
- ¾ cup of cream
- 1 teaspoon of salt
- ½ teaspoon of black pepper
- ¼ teaspoon of nutmeg
- 1 teaspoon of basil
- 1 teaspoon of garlic powder
- 2 cups shredded mozzarella cheese
- Preheat oven to 375 degree F. Butter a 8x8 baking dish.
- Wash and diced (approx. ½ inch) the potatoes (I don’t peel them). and make an even layer of potatoes in the buttered dish.
- In a medium size saucepan, melt the 2 tablespoons of butter over medium heat (2-3 minutes)
- Once the butter is melted, add the onion and cook until they are softened. (2-3 minutes)
- Add the flour and whisk until you have a smooth texture.
- Add the cream and chicken stock. Whisk until the sauce is to the desire thickness (1 minute)
- Add the salt, pepper, nutmeg, basil, and garlic powder. Cook for 1 more minute, whisking constantly.
- Pour over potatoes and mix to coat all potatoes
- Sprinkle shredded mozzarella cheese on top.
- Cover with aluminum foil and bake for 28 to 30 minutes
- Take foil off and bake for an additional 10 minutes.