Cheesy Au Gratin Potatoes (Gruyere, Cheddar, & Parmesan)

by Kayla Berman on Nov 2, 2021 (updated Nov 11, 2022) 0 comments

Cheesy Au Gratin Potatoes are pure cheesy, creamy, melt-in-your-mouth deliciousness! Thinly sliced potatoes are layered here with flavorful onion, minced garlic and topped with a gruyere, cheddar, and parmesan cheese sauce. Easy to make and absolutely delicious to eat, it’s the ultimate Thanksgiving side!

Looking for more potato recipes? Check out my Garlic Parmesan Roasted Potatoes.

Delectably Delicious Holiday Side Dish

After years of enjoying different potatoes au gratin recipes, I consider myself somewhat of a professional when it comes to the creamy, cheesy, and scrumptious dish!

My mom always asked my sisters and I what we wanted to be served at Thanksgiving dinner each year and the answer was always a resounding potatoes au gratin. I mean can you blame us? You’d be crazy to not like the dish!

But anyway, based on my pro status I can tell you that these Cheesy Au Gratin Potatoes are some of the best in the game. They’re not too soupy, not lacking in the cheese department (trust me!), and most definitely are not boring or bland.

They are thinly sliced, tender potatoes smothered in a bubbly, creamy rich sauce and finished with a crispy, cheesy crust. This dish is savory, flavorful, delicious, and truly everything you need for a perfect side dish!

Ingredients

Creamy au gratin potatoes are such a simple side dish! You need less than 10 easy ingredients. The main one being cheese, cheese, and more cheese.

The result is a delicious bubbling dish full of tender potatoes, a rich cheesy sauce, and a crispy crust! It is truly mouth watering.

Ingredient Notes

White Potatoes: Probably the most important ingredient in this cheesy potato dish is of course potatoes! You will need about 6 medium sized white potatoes.
Garlic & Onion: Garlic and onion provide tons of delicious flavor to this recipe. Add 3-5 minced garlic cloves and 1 thinly sliced onion.
Milk: You will need milk to make the deliciously creamy cheese sauce here. Use 2 1/2 cups of your milk of choice. I used 1% but 2%, whole milk, or even unsweetened almond milk would work too!
Flour: Flour is also used in the cheese sauce, as you will need to make a roux. This helps to thicken the sauce perfectly! Add 1/4 cup all purpose flour.
Butter: Again, salted butter is needed for the sauce. You will need 1/4 cup! It adds that delicious and rich flavor we all know and love.
Cheddar, Gruyere, & Parmesan Cheese: Cheese! Finally my favorite ingredient! This easy recipe calls for three different cheeses and the resulting flavor is to die for. 1 1/4 cup shredded sharp cheddar cheese, 1 1/4 cup shredded gruyere, and 3/4 cup shredded parmesan is perfect. I recommend you use block cheese and shred it yourself for the best taste!
Salt & Pepper: Lastly, season these potatoes with salt and black pepper to taste.

Substitutions & Additions

There are a few substitutions you could make to this cheesy potato recipe for it to meet your personal preferences, needs, and tastes! There also so many delicious additions you could make.

Potatoes: White potatoes are used in this recipe, but you could definitely use a different type. Like gold potatoes or red potatoes! You could even try sweet potatoes for a super fun and tasty switch up.

Bacon: Everything is better with bacon. Potatoes gratin is no exception!

Cheese: I love the combination of gruyere, cheddar, and parmesan cheese here. They are all sharp cheeses and provide an unbeatable flavor. But feel free to customize to your liking!

Spices, Herbs & Garnish: I used a touch of fresh thyme here for flavor and garnish, but adding more green would be great too – like green onions, fresh rosemary, or sage! You could also add spices to up the flavor here, maybe even something with some heat to it.

Breadcrumbs: Bread crumbs would give this casserole an even more golden and crispy crust. So good!

Season, season, season! Now this is not an addition, but it is a recommendation. Since the flavors here are pretty basic, the basics are very important. I’m talking salt and pepper! I recommend you be very generous and add to taste!

How To Make This Recipe

This cheesy au gratin recipe is the perfect addition to any main course. Especially a special occasion – like Easter, Christmas, or Thanksgiving dinner!

Step By Step Instructions

Step 1: Set the oven to 350 degrees.

Step 2: Next use a sharp knife to thinly slice the potatoes and onion. Mince the garlic cloves.

Step 3: Line the potato slices up in three rows down the center of a large prepared baking dish or casserole dish, almost like horizontal stacks. Place the onion slices in between the layers of potatoes, making sure they are evenly dispersed throughout the whole dish. Spread the minced garlic on top and add salt and pepper. Set aside.

Step 4: Next work on your cheese sauce. Start by melting the butter and flour together on the stove in a pan over medium heat. Cook for a couple of minutes until it starts to turn golden in color and creates a slightly nutty smell.

Step 5: Then add the warm milk to the flour and butter in an even stream. Whisk constantly while doing this. Then continue to whisk for about another 5 minutes, while the sauce thickens up.

Step 6: Once the sauce has thickened, turn the heat to low and add in the shredded cheese – 1 cup cheddar, 1 cup gruyere cheese, 1/2 cup parmesan. Continue whisking until the cheese melts and a creamy cheesy sauce forms. Add salt and pepper to taste.

Step 7: Then pour cheese sauce on top of the potatoes and spread evenly.

Step 8: Top the dish with the remaining 1/4 cup of each of the cheeses.

Step 9: Bake for 60 minutes.

Step 10: Serve and enjoy!

All Things Cheese Sauce

The creamy cheese sauce in this recipe is made with a simple roux. This helps to make the sauce rich, thick, and of course delicious!

I know a roux based sauce can sometimes be intimidating, but it really is as easy as can be to make. And if you follow the tips below you’ll be a pro in no time!

Tips

Melt butter and flour together until golden brown and smells slightly nutty. It should also be bubbling and simmering a bit.

Make sure the milk is warm when you add it to the butter and flour and do so in a constant stream. This helps to prevent clumping.

Whisk constantly. You want to whisk the cheese sauce throughout the entire process of making it. This once again helps prevent clumps and ensures a smooth sauce.

Once the sauce has thickened (it will be ready when it sticks to the back of a spoon), turn to low heat and add in the cheese. Melting low and slow gives the best results!

Expert Tips

Buy the blocks of cheese and shred it yourself! This will add more flavor and melt much better into the sauce.

To ensure all the potato slices are cooked to your desired texture, boil the potatoes for a few minutes before slicing and adding to the casserole dish. Just 5-10 minutes should do the trick!

Use a mandoline slicer to get evenly, thin potato slices. This will also ensure all potatoes are cooked through.

Keep the raw potatoes in cold water while you prepare the sauce. This will prevent them from going brown!

Frequently Asked Questions

What does au gratin potatoes mean?

“Au gratin” translates to “by grating” or “with a crust.” It refers to a dish that is made with cheese, breadcrumbs, and butter. It is then heated or broiled in the oven.

What is the difference between scalloped and au gratin potatoes?

Scalloped potatoes and au gratin potatoes are quite similar potato recipes!

They both involve thin slices of potatoes, and from my understanding, the main difference between the two is the dairy. Scalloped potatoes are simply potatoes cooked in heavy cream and au gratin potatoes involve cheese.

However, the two are very similar in my eyes! And to a professional, this recipe could fall more under the scalloped definition, but I’ve always known it as au gratin. So that is what I went with!

What is the preferred cheese for au gratin?

I think traditionally the best cheese to use for au gratin is gruyere! It adds an incredible smokey, rich, creamy, and salty flavor.

I also love the sharpness that cheddar and parmesan provide.

Can I prepare these potatoes ahead of time?

Totally! These cheesy potatoes can be prepared before serving in order to save time later.

This is especially great if you are serving at a holiday table like Thanksgiving or Christmas dinner!

Simply prepare these potatoes according to the instructions. But instead of baking, cover with foil and place in the refrigerator until it is time to bake and serve. I recommend only prepping 1-2 days in advance!

You could also fully bake this recipe a couple hours ahead of time (like Thanksgiving morning), allow to cool at room temperature, and place in the refrigerator until time to re-heat. Then cover with aluminum foil and place back in the oven at 350 degrees to warm throughout.

How to best serve this recipe?

This recipe is a great side dish to any main course! Like herb crusted salmon.

It is also a fantastic addition to any holiday dinner table. It will truly be the star of any Thanksgiving dinner or Easter brunch spread. Ugh, so good!

How to best store this recipe?

You can store this recipe in an airtight container in the refrigerator. It will keep for about 1 – 1 1/2 weeks!

Looking for more delicious side dishes? Check out some favorites below…

Connect with me!

If you make this cheesy au gratin potatoes recipe or any of my other recipes I would absolutely love to know! Tag me @wellnessbykay on Instagram, so I can see and share your recreations!!

Love this recipe? Leave a comment and a rating! I love to see and it helps me continue to develop delicious recipes for this blog.