Cheesy Au Gratin Mixed Potatoes

Potatoes that are sure to impress! Made with BOTH russet and sweet potatoes, covered in a delicious, but super easy, cream sauce, then topped with lots of cheese! Creamy, buttery and cheesy. You’re going to love this recipe!

russet potatoes and sweet potatoes in cream sauce with cheese

Wow. Wow. Wow. I love this recipe!! The first time I tested this recipe I arranged the potatoes in stacks in the baking dish, and the cream wasn’t able cover all the potatoes while baking, resulting in some plain, dry potatoes on top. I wasn’t impressed. BUT, the second time I test the recipe I arranged the potatoes differently, and it made a WORLD of difference. While baking, the cream sauce bubbles over the tops of the potatoes, resulting in creamy, buttery potatoes. I then finish the potatoes off with cheddar and parmesan cheese that becomes perfectly melty and crispy on top. The most dreamy combination.

Inspiration.

For years my family has been subscribed to receive the Taste of the South Magazine in the mail. A few years ago there was a gratin recipe that combined sweet potatoes with regular potatoes. We thought it was brilliant, so we tried it. Loved it! Except my dad, he doesn’t like sweet potatoes or squash. He says it’s baby food. BUT, guess what, the other day I caught him eating these potatoes, including the sweet potatoes! WIN.

Since it was a few years ago, I don’t remember the ingredients of that recipe except that they used mixed potatoes and poured heavy cream and cheese over the top. After some discussion with my mom, I decided to add nutmeg, sage and cheese to the heavy cream before pouring it over the potatoes. I feel like nutmeg is one of my mom’s secret ingredient spices. It adds a very subtle warm, nutty flavor to cream. Perfection. As well, being that I love crispy (or even burnt) cheese, I knew that I wanted to sprinkle cheese on the top of the potatoes and let it get melty and a little crispy. It really ups the flavor!

russet potatoes and sweet potatoes with cream sauce and cheese

Mixed Cheesy Gratin Potatoes Ingredients.

Russet & sweet potatoes. The combination of the two is beyond amazing. You can also use yukon gold potatoes in place of russets.

Butter. Salted butter for life.

Heavy whipping cream. 1 pint aka 2 cups. What I love most about this recipe is that you don’t have to make a roux and thicken the sauce on the stove like a lot of gratin potato recipes. You simply mix the cream with butter, cheese and spices, then pour it over the potatoes and let the oven do the work.

Garlic. I prefer fresh garlic, but you could use garlic powder if you’re in a pinch.

Ground nutmeg & sage. The perfect duo.

Lots of cheese. Grated parmesan gets mixed into the cream cheese. Shredded parmesan and cheddar cheese gets sprinkled over the top of the potatoes during the last 10 minutes of baking.

russet potatoes and sweet potatoes baked with cream sauce and melted cheese

Tips & Tricks.

Slicing the potatoes. After peeling the potatoes, I used a knife to cut them into thin slices. You could also use a mandoline slices.

Potatoes. I used russet potatoes, but you could also use yukon gold potatoes. Also, I technically didn’t use sweet potatoes, I used yams. In the United States, yams are actually most commonly sold at grocery stores, but labeled as sweet potatoes.

Make ahead. This dish can be made one day ahead of time. Place the potatoes and cream in the baking dish and cover tightly with tinfoil. Place in the refrigerator. Remove the baking dish from the refrigerator while the oven preheats. Being that the potatoes and cream will be cold, you may need to add an extra 10 minutes onto the baking time.

baked cheesy gratin russet potatoes and sweet potatoes
cheesy gratin potatoes

Mixed Cheesy Gratin Potatoes

Potatoes that are sure to impress! Made with both russet and sweet potatoes, covered in a delicious, but super easy, cream sauce, then topped with lots of cheese! Creamy, buttery and cheesy. You're going to love this recipe!
Prep Time 30 mins
Cook Time 1 hr 10 mins
Total Time 1 hr 40 mins
Course Dinner
Servings 10 servings

Ingredients
  

  • 2 – 2 1/2 pounds russet potatoes (about 4 large potatoes)
  • 2 – 2 1/2 pounds sweet potatoes (about 4 large potatoes)
  • 3 tablespoons salted butter, divided
  • 2 cups heavy whipping cream
  • 1/2 cup grated parmesan cheese
  • 3 garlic cloves, minced
  • 1/4 teaspoon ground nutmeg
  • 1/2 teaspoon ground sage
  • 1 teaspoon salt
  • 1/4 teaspoon pepper
  • 1 cup sharp white cheddar cheese, shredded
  • 1 cup parmesan cheese, shredded
  • If desired, fresh thyme and flakey sea salt for garnishing

Instructions
 

  • Peel and thinly slice potatoes using a knife or mandoline slicer.
  • Preheat oven to 400 degrees F. Grease a 3 quart or 9×13 inch baking dish with 1 tablespoon of butter.
  • Arrange potatoes in prepared baking dish. I stacked the potatoes on their sides, alternating russet and sweet potatoes. Alternatively, you can randomly lay potato slices flat in the baking dish.
  • Melt 2 tablespoons of butter. In a medium bowl, whisk together melted butter, heavy whipping cream, grated parmesan cheese, garlic, nutmeg, sage, salt and pepper. Evenly pour the mixture over the potatoes, making sure to cover all the potatoes.
  • Cover with tinfoil and bake for 45 minutes. Remove foil and bake another 15 minutes. Sprinkle potatoes with shredded cheddar and parmesan cheese. Bake an additional 10-15 minutes until the cheese is melty and slightly browned.
  • Let the potatoes rest for about 15 minutes before serving. If desired, garnish with fresh thyme and flakey sea salt.
Did you make this recipe?I’d love to hear from you! Rate the recipe and leave a comment below or share a picture on Instagram and tag @ModernFarmhouseEats

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Vivian
Vivian
6 days ago

I made these for Easter dinner, they were loved by everyone. Definitely a keeper! I have enough ingredients to make another batch and was wondering if they will freeze well?