Au Gratin Potatoes

Creamy Au Gratin Potatoes are an easy, impressive Thanksgiving or Christmas side dish that I make every year, and everyone looks forward to it. Thinly sliced layers of potatoes are tossed in a rich and flavorful cheese sauce and baked until bubbly and golden. Every bite is delicious!

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Au Gratin Potatoes Video

I’ll show you, step by step, how to make this creamy, cheesy au gratin potato side dish that will be the star of your holiday table. These potatoes are so luxurious, yet so easy to make!

Cheesy Au Gratin Potatoes Recipe

“Au Gratin” (also called Gratin Dauphinois) is a French cooking technique that involves baking potatoes in cream, with decadent layers of grated gruyere cheese.

This Au Gratin Potatoes recipe is a showstopping potato side dish that I like to make for the major holidays because it tastes and looks so special. Pair this with Baked Ham and Juicy Roast Turkey for a memorable holiday feast! This potato casserole is absolutely holiday-worthy, but simple to prepare, especially with our quick method for thinly slicing the potatoes (see below).

Potatoes Au Gratin Ingredients

The secret to making the perfect au gratin potatoes is in this recipe’s simple yet flavorful ingredients. Below is an overview of what you’ll need, with the full details available in the recipe card.

• Butter and Flour – You’ll whisk together melted butter and flour to form a roux, which is the base for the cream sauce.
• Milk and Cream – Adding a bit of heavy cream will prevent it from curdling or breaking. Milk keeps it light and moist.
• Seasoning – We season the cream sauce with onion powder, garlic powder, salt, and pepper.
• Gruyere Cheese – Gruyere is a hard Swiss Alpine cheese that’s smooth and great for melting. You can substitute grated sharp white cheddar or a blend of mozzarella and parmesan cheese.
• Potatoes – We love using Yukon gold potatoes for this au gratin recipe, but other starchy potatoes, like russet potatoes, will also work. You can peel the potatoes or leave them unpeeled; it’s up to you.

3 Ways to Thinly Slice Potatoes

The key to having the au gratin potatoes cook through evenly is to evenly and thinly slice the potatoes. to 1/8″ thick. Below are our tried-and-true methods to achieve perfect, thinly sliced potatoes for this recipe:

• Knife – We love our santoku for slicing potatoes. It has handy grooves that keep the food from sticking to the knife.
• Food Processor – The food processor is our favorite method for thinly sliced potatoes. It’s definitely the fastest and most efficient, and it feels safer since you aren’t getting close to the blade. We use a level 1 blade on our Cuisinart. 
• Mandolin Slicer – I recommend using the food holder that comes with a mandolin, as well as a safety glove to protect your fingers, as those blades can be sharp! Slice off one end of the potato to create a flat surface for the holder to grab onto, and follow the manufacturer’s instructions when slicing.

How to Make Au Gratin Potatoes

• Make the Cheese Sauce – Start by making the roux – whisk butter and flour in a large pot or dutch oven until golden. To prevent lumps, slowly whisk in the milk and cream, then season to taste and continue to stir until thickened. Once the pot is off the heat, stir half of the shredded Gruyère into your creamy sauce.
• Slice the Potatoes –  Slice your peeled or unpeeled potatoes into rounds about ⅛” thick (see above).
• Combine – Toss the potato slices in the cream mixture until well coated, then transfer the potatoes to a buttered casserole dish. Cover everything in a generous layer of the remaining grated cheese.
• Bake – Cover the potatoes with foil and bake at 350ºF for 1 hour, then uncovered for 15-30 minutes until tender and the sauce is bubbling. For even more browning on top of your au gratin potatoes, broil for a couple of minutes at the end.

How to Serve Au Gratin Potatoes?

We love to serve these au gratin potatoes with a sprinkle of fresh chives or fresh chopped parsley, as a satisfying Thanksgiving or Christmas side dish, or with family meals throughout the colder months. Here are some ideas to build your menu:

• Turkey – Serve as a holiday side dish with Spatchcock Turkey and Turkey Gravy.
• Roasts – Roasted Beef Tenderloin, Prime Rib, or Spatchcock Chicken.
• Veggies – Pair with Oven-Roasted Broccoli, Roasted Carrots, and Roasted Cauliflower.
• Salad – As a tasty side next to a fresh Beet Salad or Cobb Salad.

Make-Ahead & Storage

This cheese-filled potato bake is perfect to make ahead, and easy to store for delicious leftovers.

• Make-Ahead: I recommend baking the casserole completely, then cooling to room temperature, covering, and refrigerating. When you’re ready to serve, reheat per the instructions below.
• To Refrigerate Leftovers: Once the baked casserole has cooled, cover and store in the refrigerator for up to 4-5 days.
• Freezing: Baked and cooled gratin potatoes can be wrapped tightly and frozen for up to 2 months. Thaw the potatoes in the fridge before reheating.
• To Reheat: Reheat baked au gratin potatoes in the oven covered in foil, at 350ºF for about 25 minutes or until hot throughout. You can also reheat in the microwave.

Hearty homemade Au Gratin Potatoes are the best comfort food. We’re sure that you’re going to love making these this holiday season, and all winter long!

More Potato Side Dishes

If you love this au gratin recipe, below are more must-have potato recipes.

• Twice-Baked Potatoes
• Loaded Potato Soup
• Mashed Potato Pancakes
• Garlic Mashed Potatoes
• Perfect Roasted Potatoes
• Shepherd’s Pie
• Creamy Mashed Potatoes
• Smashed Potato Salad
• Ranch Scalloped Potatoes