If you’re looking for the ultimate comfort food side dish, this Classic Potatoes Au Gratin recipe is rich, creamy, and loaded with cheesy goodness. Made with buttery onions and garlic, layered with tender potatoes, and baked in a velvety white cheddar and parmesan cheese sauce, it’s the perfect side for weeknight dinners, holidays, or special occasions.

Best of all? This dish is made with simple ingredients and bakes beautifully in an 8 x 8″ dish for smaller gatherings—but you can easily double it in a 13 x 9″ dish. Doubling it should get you 6 – 8 servings, or insures you’ll have leftovers.

Classic Potatoes Au Gratin is made with buttery onions and garlic, layered with tender potatoes in a cheesy sauce.

Why You’ll Love This Old Fashioned Potatoes Au Gratin Recipe

Rich and creamy cheese sauce – Made from scratch with real ingredients.
Perfectly tender potatoes – No need to pre-boil.
Versatile serving sizes – Make it for 4 or double for 6–8 people.
Crowd-pleasing comfort food – Elegant enough for holidays, easy enough for weeknights.

A rich and creamy side dish that is a classic comfort food.

Making Classic Potatoes Au Gratin

First, preheat your oven to 350°F, then lightly grease an 8 x 8” baking dish and set aside.

Next, in a medium saucepan, melt the butter over medium-low heat. Add the chopped onion and cook until soft and translucent, about 5 minutes. Then, stir in the garlic and cook for another 30 seconds, just until fragrant.

Next, start the cheese sauce. Sprinkle in the flour and stir constantly for 1 minute to form a roux. Slowly whisk in the chicken broth, then the milk, whisking constantly to avoid lumps and to thicken. Bring to a boil over medium heat, and season to taste with salt and pepper.

Layer: Arrange 1/3 of the sliced potatoes in the prepared dish. Then, pour 1/3 of the cheese sauce over the potatoes, and sprinkle 1/3 of the cheddar cheese across the top. Repeat two more times: potatoes, sauce, cheddar cheese.

Lastly, sprinkle the Parmesan cheese evenly over the top, and cover with foil.

Bake for 45 minutes, then carefully remove the foil. Continue to bake uncovered for another 45 minutes, or until the potatoes are fork-tender and the top is golden and bubbly.

Let cool for 10 minutes before serving to allow the sauce to set.

Classic Potatoes Au Gratin is easy to make and can easily be doubled into a 13x9" dish.

Helpful Hints & Doubling Tips

Make Ahead: Assemble the dish up to 24 hours in advance. Cover and refrigerate. When ready to bake, add an extra 10 minutes to the covered baking time.
Double the Recipe: To serve 6–8 people, double all ingredients and use a 13 x 9” baking dish. Bake as directed, adding 10–15 extra minutes (if needed) for tenderness.
Use Blocks of Cheese and grate yourself for a cheesier, smoother sauce. Buying pre-shredded is convenient, but they have starchy preservatives that don’t allow the cheese to melt as nicely.
Freezing may change the texture and flavor, so if you absolutely must freeze, seal tightly for up to two weeks.
Layer for even baking. Take this time to make three layers to insure the potatoes are evenly coated with the sauce and cheddar cheese.

What to Serve with Potatoes Au Gratin

This dish pairs beautifully with:

Baked Chicken Tenders or Parmesan Chicken
The Best Sloppy Joes
Glazed ham
Grilled steaks or pork chops
Asian or Turkey Meatloaf
Steamed green beans or a crisp side salad

Each potato slice is smothered in white Cheddar cheese, Parmesan cheese, onions, and butter.

Storage & Reheating

Refrigerate: Store leftovers in an airtight container for up to 4 days.
Reheat: Warm in the oven at 350°F or microwave individual portions until heated through.

If you tried and love this recipe, please leave a 5-star rating on the recipe card and consider leaving a comment below. Thank you so much.

Print Recipe Pin Recipe Rate this Recipe

No ratings yet

Classic Potatoes Au Gratin

This Classic Potatoes Au Gratin with White Cheddar and Parmesan is a must-try for cheese lovers and comfort food fans. With a silky homemade cheese sauce, tender potato layers, and a golden crust, it’s the kind of dish that steals the show—whether on a holiday table or alongside your favorite weeknight main.

Prep Time20

Cook Time1 30

Total Time1 50

Course: Side Dish

Cuisine: American

Keyword: cheesy, comfort food, from scratch, old fashioned

Servings:

Calories: 379kcal

Author: Sweet Ordeal

Ingredients

2 Tbsp. unsalted butter
1 small onion, chopped
2 cloves garlic, minced
2 Tbsp. all-purpose flour
1/2 cup chicken broth low sodium
1 cup milk or half and half
1/4 tsp. salt (or more to taste)
1/4 tsp. black pepper (or more to taste)
1 1/2 lbs. Red or Yukon Gold potatoes, thinly sliced (approx. 1/8")
1 cup white cheddar cheese, freshly grated
1/4 cup Parmesan cheese, freshly grated

Instructions

Preheat oven to 350°F and lightly grease an 8 x 8" baking dish with butter or nonstick spray.
In medium sauce pan, melt butter over medium-low heat. Add onion and cook until soft and translucent, about 5 minutes. Stir in the garlic and cook for another 30 seconds, just until fragrant. Sprinkle flour over the top and whisk for 2 minutes.
Gradually add the chicken broth and milk while constantly stirring to thicken. Whisk until smooth. Bring to a boil over medium heat while whisking, season with salt and pepper.
Layers: Place 1/3 of the sliced potatoes in the bottom of the prepared dish, followed by 1/3 of the sauce and 1/3 of the cheddar cheese. Repeat layers 2 more times: potatoes, sauce, cheese. Top with Parmesan cheese. Cover with foil.
Bake for 45 minutes. Remove cover and continue baking for another 45 minutes. The top should be a golden brown and the potatoes should be fork tender. Enjoy!