Potatoes Au Gratin

5 from 1 vote

Tender potato slices laced with sweet onions smothered in a creamy cheese sauce with a hint of garlic. This potatoes au gratin recipe is the perfect side dish to any meal!

Prep Time 20

Cook Time 1 30

Total Time 1 50

Servings

Calories 393kcal

Author David & Debbie Spivey

Ingredients

▢ 4 large russet potatoes sliced into ⅛-inch slices
▢ ½ onion thinly sliced into ⅛ to ¼-inch rings (optional, but highly recommended)
▢ Kosher salt and freshly cracked black pepper to taste
▢ 2 tablespoons unsalted butter
▢ 2 tablespoons all-purpose flour
▢ 1 cup whole milk
▢ 2 teaspoons garlic powder
▢ 1 cup extra-sharp cheddar cheese shredded
▢ fresh parsley for garnish, (optional)

Instructions

Preheat oven to 400 degrees F. Butter a 2-quart casserole dish.¼
Add potato and onion slices to the casserole dish and toss so that they layer with each other, but lay flat. Season with salt and pepper, to taste.
In a medium-size saucepan over medium heat, melt butter until it just begins to foam. Mix in the flour and season with salt, to taste, while stirring constantly for one minute, with a wooden spoon. After one minute, stir in the milk. Switch to a whisk and continue to stir and cook until the mixture is smooth and has thickened.
When the sauce is thick and bubbling, it should coat the back of a spoon, and leave a space when pulling your finger through the sauce. Stir in cheese and garlic powder all at once, until melted.
Pour cheese over the potatoes and onions, and cover the dish with aluminum foil. Bake covered for about an hour. After 60 minutes, uncover and check for tenderness. Continue to back uncovered, until potatoes and onions are tender and the cheese sauce begins to brown around the edges, about 30 minutes.
Remove and allow to cool about 10 minutes before serving. Top with fresh parsley if desired.

Notes

Slice Potatoes Evenly: Aim for slices about ⅛ inches thick for uniform cooking. Use a Mandoline Slicer if you have one, but a sharp knife works just fine.

Onions: for added flavor, but feel free to omit them for picky eaters.

Season Each Layer: Don't forget to season each layer with salt and pepper to taste.

Good Melting Cheese: Use any cheese or combination of cheeses that melt well. Sharp Cheddar, Gruyère, Gouda Cheese or Fontina. Avoid pre-shredded cheese, which contains additives that affect melting.

Thicken the Sauce Fully: The roux should be cooked at least a minute before adding the milk. The sauce should coat the back of a spoon before adding cheese.

Tenderize the Potatoes: Bake this dish covered for at least an hour, then uncover to brown the top.

Cooling: Cool for 10 minutes before serving to allow the sauce to set.

Nutrition

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