Potatoes Au Gratin
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Potatoes Au Gratin

Tender potato slices laced with sweet onions smothered in a creamy cheese sauce with a hint of garlic. Potatoes au gratin the perfect side dish to any meal!
Course Side Dish
Cuisine American
Keyword potatoes au gratin, scalloped potatoes
Prep Time 20 minutes
Cook Time 1 hour 30 minutes
Total Time 1 hour 50 minutes
Servings 4
Calories 393kcal
Author David & Debbie Spivey


  • 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 fresh 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)


  • Preheat oven to 400 degrees F. Butter a 2-quart casserole dish.
  • 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.


There are recipes where I have seen the potatoes sliced thin and placed upright into a casserole dish to makes for a very pretty presentation. I love pretty food, but it doesn't make them taste any better.
I have also left out the onions for my stepson and grandson, but if you and your family love onions, don't leave them out! They add so much more flavor to this wonderful dish.
Recipe adapted from AllRecipes.com


Calories: 393kcal | Carbohydrates: 47g | Protein: 14g | Fat: 17g | Saturated Fat: 10g | Cholesterol: 50mg | Sodium: 214mg | Potassium: 1034mg | Fiber: 3g | Sugar: 5g | Vitamin A: 555IU | Vitamin C: 13.1mg | Calcium: 303mg | Iron: 2.3mg
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