Cheesy Au Gratin Potatoes

This post was last updated on December 6, 2014 to include new images.

Cheesy Au Gratin Potatoes

Is it just me, or do you get confused between au gratin potatoes and scalloped potatoes, too?

Not sure why it’s so difficult for Dustin and me to remember, but I guess it’s just one of those many things.

Cheesy Au Gratin Potatoes - Raw PotatoesCheesy Au Gratin Potatoes - Raw Potatoes

Last week, while Dustin and I discussed (for probably the twentieth time) which one was the “cheesy one” and which one was the “milky one,” I decided I’d do my own problem-solving.  Over the years, I have learned that, if I make it, I remember it.  For the most part.

Cheesy Au Gratin Potatoes - Ingredients

So I did some research on the matter and re-learned (again…sigh) it’s the au gratin potatoes I prefer. Because…well…they’re cheesy and baked until golden and crispy.

What’s NOT to like?

Cheesy Au Gratin Potatoes - Mushrooms

Scalloped potatoes, on the other hand, are the milk-based potato dish. Nothing against milk, but I’m a cheesy kinda girl. Wait a minute…that didn’t come out right.  Ugh.  Well, you get what I mean.


Cheesy Au Gratin Potatoes - Ready To CookCheesy Au Gratin Potatoes - Mmm Cheese Sauce

Now that the definition was settled and I was confident to clearly declare my understanding of cheesy au gratin potatoes once more, it was time to make them.

But, why stop at just the cheese?

Cheesy Au Gratin Potatoes - Adding Cheese On TopCheesy Au Gratin Potatoes - Baked

I wanted to go all out with these au gratins by adding additional flavors to the cheesy potato goodness.

I brought in the big guns: bacon and mushrooms.

Cheesy Au Gratin Potatoes

Yup.  And it was goooood.

Cheesy Au Gratin Potatoes

This tasty side also makes a great side dish for a Christmas ham so keep them in mind as the holidays get closer!

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If you give this recipe a try, let me know what you think by leaving a comment and rating it. And don’t forget to take a picture and tag it #asweetpeachef on Instagram! I LOVE seeing what you come up with. Enjoy!

Cheesy Au Gratin Potatoes
Prep time
Cook time
Total time
These delicious Cheesy Au Gratin Potatoes have added bacon and mushrooms for extra yummy flavor.
Recipe type: Easy
Serves: 4-6
  • 3 medium russet potatoes, sliced between ⅛ and ¼-inch thick
  • 8 cremini mushrooms, small diced
  • ½ large yellow onion, small diced
  • 4 strips bacon, chopped
  • 2 cloves garlic, minced
  • 1 tsp. kosher salt, plus more to taste
  • ¼ tsp. ground black pepper, plus more to taste
  • 3 tbsp. unsalted butter
  • 3 tbsp. all-purpose flour
  • 2 cups milk
  • 1½ cups PLUS ½ cup shredded cheddar cheese, divided
  • ⅛ tsp. garlic powder
  1. Heat oven to 400 degrees.
  2. Place potato slices in a microwave-safe bowl and microwave on high for 6 minutes. This will save significant time baking, as it will start to cook the potatoes. If you're wanting to line the potato slices into a neat domino format (as pictured above), do this before heating in the microwave. Lining them up makes for a better presentation, but is not necessary.
  3. Over medium-high heat, cook bacon for 3-5 minutes, or until it begins to sweat.
  4. Add onion and mushrooms and cook until tender. Add garlic and cook for one additional minute. Remove from heat.
  5. In a medium sauce pan, melt butter over medium heat. Mix in flour and kosher salt, stirring constantly. Cook for one minute.
  6. Add the milk and stir to combine. Continue to cook, stirring very frequently, until mixture has thickened.
  7. Stir in 1½ cups of the cheddar cheese all at once and stir until melted. Continue to stir for one minute after cheese is melted.
  8. Add in the garlic powder and check for seasoning. Add any additional salt or pepper as needed.
  9. Combine the onion-mushroom-bacon mixture with the cheese sauce.
  10. If you lined the potato slices like dominos, just pour the cheesy onion contents over the potatoes and then giggle the baking dish some to get it to settle in the crevices. If you'd prefer to just combine it all together and not worry about the slices being in an orderly fashion, just gently toss to combine, making sure to coat the potatoes as evenly as possible, and then pour into the baking dish.
  11. Sprinkle the remaining ½ cup of the cheese evenly over the top.
  12. Bake, covered with aluminum foil, for 40-50 minutes, until potatoes are completely tender. Remove aluminum foil and bake, uncovered, for an additional 10-15 minutes until top is golden brown.


  1. BecBec says

    Hello! I would love to try making these for Christmas but am worried my one oven will not allow for it time wise… Could these be made in a slow cooker? Or do you think they would hold up well being made beforehand as reheated? I’d love your opinion!

    • says

      I’ve never tried to make this recipe in a slow cooker before so I’m not sure. I think reheating would be fine, but I’d recommend reheating in the oven if you have the space to keep the same texture. If not, the microwaved version will still be tasty :)

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