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Potato Gratin

Potato Gratin, also known as potatoes au gratin, is a decadent side dish for any occasion. This classic recipe is sure to make any meal truly feel like a holiday!

White plate with a serving of potato gratin. A second plate is in the background

When I was a kid, I loved and I mean, LOVED potatoes au gratin – although they were straight from a Betty Crocker box, they were totally one of my very favorite weeknight meals.

Sometimes my mom served them as a side with chicken and other times, she’d mix in some veggies and kielbasa for a one-pan dinner.

Since becoming an adult, I’m not too keen on the boxed version of potato gratin; however, I still love instant mashed potatoes and gravy – especially if they’re from KFC.

After eating potato gratin at one of favorite steak houses last month, I decided it was time to whip up this decadent side dish at home, just in time for Thanksgiving.

Potato gratin ingredients arranged on a gray countertop

WHAT IS POTATO GRATIN?

A gratin is a dish that is topped with a browned crust, oftentimes breadcrumbs or cheese. Gratins are usually cooked in a shallow dish and finished under a broiler to get that beautifully brown, crispy top.

Potato Gratin, also known as potatoes au gratin, au gratin potatoes, or gratin dauphinois, is the potato version of this. Thinly sliced potatoes are layered with cream, garlic, and cheese and finished under the broiler.

Spoon stirring cream sauce in a saucepan

MY FAVORITE POTATO GRATIN RECIPE

My Potato Gratin recipe is pretty traditional. After all, why fix something that isn’t broken?

Because these potatoes are pretty traditional, you’ll find plenty of decadent ingredients in them like heavy creamy and gruyere (or white cheddar) and parmesan cheeses. 

thinly sliced potatoes soaking in cold water in a white bowl

That means the final dish is pretty rich and decadent – these aren’t “low fat” potatoes by any means! But for a special occasion? You bet they are at the top of the list of my favorite side dishes.

Serve these au gratin potatoes with honey glazed carrots and air fryer brussels sprouts or a shaved brussels sprout salad and you’ll have the perfect pairing with your holiday turkey or ham.

And if you’re looking for a side dish recipe that you can prepare the day before, this is totally it! Keep reading to find out how to make this Potato Gratin ahead of time.

Sliced potatoes and cream sauce layered in a white baking dish, ready to bake

HOW TO MAKE AU GRATIN POTATOES

Like a lot of recipes that are French in origin, this recipe might seem fiddly, but I promise it’s totally doable. 

The recipe can be broken down into a few pretty simple steps:

  • Prep the cream sauce
  • Slice the potatoes 
  • Layer the gratin
  • Bake!
Shredded cheese on top of a baked potato gratin, ready to go under the broiler

To prep the cream sauce, combine heavy cream, shallots, garlic, salt, pepper, and thyme in a saucepot. Bring this to a simmer and let it cook for about 15 minutes, until the shallot and garlic are tender.

Use a stick blender or a traditional blender to blend the sauce until it is smooth. I like to use a stick blender for this. If you’re using a traditional blender, be VERY careful since the mixture is hot.

While the cream sauce is simmering, you can slice the potatoes. I use a mandolin to do this so they are all the same thickness. You want them to be about ⅛-inch thick.

Overhead view of a baked potato gratin, ready to serve

After you’ve sliced the potatoes, pop them in a bowl of cold water to help get rid of some of the excess starch and keep them from oxidizing.

When the cream sauce is ready, layer the (drained) potatoes across the bottom of a buttered baking dish, then pour the cream over the potatoes.

Cover the pan with foil and bake for about an hour, or until the potatoes are tender.

Serving of potato gratin being lifted out of a white casserole dish

Remove the foil and top with a mixture of gruyere or sharp white cheddar cheese and parmesan cheese. Place the potatoes under the broiler for about 5-10 minutes until the cheese is melted and the top is golden brown.

Be sure to keep a close eye on the potatoes while they’re under the broiler! They can go from perfectly golden to burnt pretty quickly, so don’t wander too far away while they’re browning.

Fork alongside a serving of potato gratin on a white plate

PLANNING AHEAD

If you’re planning ahead and figuring out what you can make the day before, add this Potato Gratin to that list. 

To make your Potato Gratin ahead of time, assemble the dish and bake it, covered with foil, for 50-60 minutes. Let it cool and then refrigerate overnight.

When you’re ready to serve, cover the potatoes with foil and reheat them in a 350°F oven for about 20 minutes or until hot.

Uncover the potatoes, top with the cheeses, and broil for 5-10 minutes.

Voila! You’ll impress everyone with this luxe side dish – you don’t have to tell them that it wasn’t that hard to make. That’s our secret.

Overhead view of two white plates of potato gratin on a gray countertop
Fork alongside a serving of potato gratin on a white plate

Potato Gratin

Yield: 10-12 servings
Prep Time: 25 minutes
Cook Time: 1 hour 15 minutes
Total Time: 1 hour 40 minutes

Potato Gratin, also known as potatoes au gratin, is a decadent side dish for any occasion. This classic recipe is sure to make any meal truly feel like a holiday!

Ingredients

  • 1 tablespoon unsalted butter, room temperature
  • 2 ½ cups heavy cream
  • 2 medium shallots, quartered
  • 4 garlic cloves, smashed
  • 1 tablespoon fine sea salt
  • 1 teaspoon fresh ground black pepper
  • 1 tablespoon fresh thyme
  • 4 pounds Yukon gold potatoes
  • 4 ounces shredded gruyere or sharp white cheddar cheese
  • 1 ounce shredded parmesan cheese

Instructions

  1. Preheat oven to 350°F. Use the butter to coat the inside of a 13x9-inch baking dish. Set aside.
  2. In a saucepan, combine heavy cream, shallots, garlic, salt and pepper, and thyme. Bring to a gentle simmer and cook until shallot and garlic are softened, about 15 minutes. Transfer to a blender or stick blend until smooth. If using a traditional blender, be VERY careful as the mixture will be hot.
  3. While the cream mixture is cooking, slice potatoes using a mandolin to ⅛-inch thickness and  transfer a bowl of water to get rid of excess starch and prevent browning. After all potatoes are sliced, drain sliced potatoes well.
  4. Take the sliced potatoes and shingle them across the bottom of the baking dish, filling in any gaps with smaller pieces of potato. Pour the blended cream mixture evenly over the potatoes.
  5. Cover with foil and bake for 50-60 minutes or until the potatoes are fork tender. Remove foil, top with grated cheeses and return to oven with oven rack closest to the broiler and  broil for 5-10 minutes until the cheese is super melty and golden brown.

To prep ahead of time:

  1. The day before, assemble the dish and bake, covered with foil, for 50-60 minutes. Allow to cool and refrigerate overnight. When ready to serve, reheat in a 350°F oven, covered with foil, for 20 minutes or until hot, uncover, top with the cheeses and broil for 5-10 minutes.

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Nutrition Information
Yield 12
Amount Per Serving Calories 383Total Fat 24gSaturated Fat 15gTrans Fat 1gUnsaturated Fat 7gCholesterol 73mgSodium 681mgCarbohydrates 35gFiber 4gSugar 4gProtein 10g

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