Easy Au Gratin Potatoes Recipe

This au gratin potatoes recipe features tender, thinly sliced potatoes layered with a velvety cheese sauce made from sharp white cheddar and Gruyère. Though it takes a little over an hour to bake, it’s made all in one dish for easy prep and cleanup. A perfect make-ahead or holiday recipe.

Easy Au Gratin Potatoes Recipe

• One-pan recipe: You can make this dish all in one oven-safe pan—less mess, more flavor.
• Ultra comforting and flavorful: Sharp cheddar, Gruyère, and herbs make it rich, savory, and perfect for sharing.

Ingredients for Au Gratin Potatoes

• Butter: Adds richness and is essential for making the roux that thickens the cheese sauce. Salted or unsalted will both work.
• Flour: Stick with all-purpose flour to thicken the sauce.
• Half and Half: Makes the sauce creamy without being too heavy. You can use equal parts whole milk and heavy cream as a substitute.
• Herbs & Spices: Garlic powder, onion powder, dried thyme, rubbed sage, and plenty of salt and pepper are the easiest way to add tons of savory flavor to these au gratin potatoes.
• Dijon Mustard: Boosts the flavor and sharpness of the cheese. Regular mustard or a splash of white wine vinegar can work as substitutes.
• Sharp White Cheddar Cheese: Melts smoothly and adds bold cheesy flavor. Use regular cheddar if preferred.
• Gruyère Cheese: Offers a nutty, rich flavor and gooey texture. Swiss cheese is a milder substitute.
• Russet Potatoes: Starchy and sturdy, which makes them ideal for baking. Yukon golds can also be used but will be slightly creamier. I like to peel the potatoes when I make them au gratin.
• Yellow Onion: Adds sweetness and depth. Shallots or white onion also work.

How to Make Au Gratin Potatoes

In a large sauté pan over medium heat, melt butter. Whisk in flour and cook for 1–2 minutes until lightly golden.

Slowly add half and half, whisking constantly. Let it thicken for 3–4 minutes. Stir in garlic powder, onion powder, salt, pepper, thyme, sage, and Dijon. Lower heat and add cheddar and half the Gruyere.

Stir until smooth and creamy.

Layer pan with 1/3 of the sauce, half the potatoes, half the onions and a few pinches of salt and pepper.

Add half the remaining sauce.

Layer remaining potatoes and onions.

Add the remaining sauce.

Top with the rest of the Gruyère.

Cover with foil and bake for 40 minutes. Remove foil and bake uncovered for 25–30 minutes until golden and bubbly.

Let it rest for 10 minutes to thicken before serving. Garnish with chopped fresh parsley if desired.

Tips for Making Au Gratin Potatoes

• You don’t need a mandoline for this recipe! Although, if you have one by all means use it – but it’s not required. A regular ol’ sharp knife will work just fine and all the slicing really doesn’t take as much time as you think it might.
• Shred your own cheese! Freshly shredded cheese will melt the best and add more delicious flavor than pre-shredded cheese.
• The cheese sauce will be super cheesy and might be a bit stringy, that’s okay. Just cook it until it’s smooth and creamy.
• Taste the sauce before assembling! Add more salt and pepper to taste before layering everything together.
• Don’t skip the rest time! This helps the sauce set up and get super creamy.

Make-Ahead Instructions

• If you want to cut the potatoes ahead of time, just store them covered, in a bowl of water in the fridge.
• Dry potatoes a bit before adding them as they will release liquid as they cook as well.
• This will ensure the au gratin potatoes aren’t soggy or wet, but smooth and creamy.
• You can also assemble the dish up to a day in advance.
• Cover tightly with foil and refrigerate.
• Let sit at room temperature for 30 minutes before baking.
• You may need to add 5–10 minutes to the bake time to account for the colder temperature.

Storing Leftovers

• Store leftover au gratin potatoes in an airtight container in the refrigerator for up to 4 days.
• The flavors deepen over time, making leftovers even better.

Freezing Au Gratin Potatoes

• Freeze baked and cooled potatoes in a freezer-safe container for up to 2 months.
• Thaw overnight in the fridge before reheating.
• Note: the texture may be slightly less creamy after freezing, but still delicious.

Reheating Au Gratin Potatoes

• Reheat covered in a 350 degree oven for 20–25 minutes, or until warmed through.
• You can also reheat individual portions in the microwave in 30-second intervals.
• Season to taste with salt and pepper before serving.

Serving Suggestions

• glazed crock pot ham
• ham and cheese sliders
• easy Salisbury steak
• sloppy joe biscuits
• crock pot country style ribs
• easy beer brats

Try these easy side dish recipes next!