This Cheesy Potatoes Au Gratin recipe is perfect for celebrating the holidays with friends and family! Sharp cheddar cheese takes it to a whole new level.
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5 from 6 votes

The​ ​Cheesiest​ ​Potatoes​ ​Au​ ​Gratin

This Cheesy Potatoes Au Gratin recipe is perfect for celebrating the holidays with family!
Prep Time30 mins
Cook Time1 hr 10 mins
Total Time1 hr 40 mins
Course: Side Dish
Cuisine: American
Keyword: potatoes au gratin
Servings: 12
Calories: 356kcal
Author: Jennifer Farley


  • 3 1/2 pounds russet potatoes (about 5 medium)
  • 4 ounces unsalted butter, plus more for greasing the pan
  • 1 medium yellow onion, diced
  • 1 clove garlic, minced
  • 1/4 cup + 2 tablespoons all-purpose flour
  • 2 teaspoons kosher salt, plus more as needed
  • 1 teaspoon ground black pepper, plus more as needed
  • 4 cups half-and-half (whole milk may be substituted)
  • 4 cups Borden® Cheese Sharp Cheddar Shreds, divided
  • Optional for serving: chopped fresh chives and fresh ground black pepper


  • Preheat oven to 400 degrees F. Generously butter a 3 1/2-quart casserole dish (see notes).
  • Peel potatoes and slice to approximately 1/6-inch thin on a mandolin (or using a knife). Submerge completely in a large bowl filled with cold water to prevent oxidation.
  • In a medium-sized saucepan, heat 2 tablespoons of the butter over medium-low heat. Add the onions and garlic. Cook, stirring periodically, until translucent, 3-5 minutes. Turn up the heat to medium and cook for an additional minute, stirring, until the onions have caramelized slightly.
  • Add the remaining butter. Mix in the flour and whisk constantly for 2-3 minutes to cook out the flour taste. Stir in half-and-half, salt and pepper, then whisk until mixture has thickened, 3-5 minutes. Remove from the heat, and add 3 cups of the cheese in handfuls. Continue stirring until melted, about 30 to 60 seconds.
  • Drain the potatoes, using paper towels to pat away excess water. Layer half evenly in the casserole dish. Pour half the cheese over the potatoes and top with 1/2 cup cheddar cheese. Repeat with the remaining potatoes, cheese sauce and shredded cheddar. Cover the casserole dish with a tight-fitting lid or aluminum foil.
  • Bake for 45 minutes, then remove the foil. Bake for another 15-20 minutes, until the top is golden. For the final few minutes, you can optionally turn on the broiler to further crisp up the top. If you do this, keep a very close eye on it!
  • Remove from the oven. If using, top individual servings with chives and freshly ground black pepper.



I used a 3 1/2 quart round casserole dish, but any rectangle or square dish that holds 3 1/2 to 4 quarts will work. If you’re not sure how much your casserole dish holds, test it by adding water.


Calories: 356kcal | Carbohydrates: 31g | Protein: 14g | Fat: 15g | Saturated Fat: 9g | Cholesterol: 58mg | Sodium: 659mg | Potassium: 694mg | Fiber: 1g | Sugar: 1g | Vitamin A: 600IU | Vitamin C: 9mg | Calcium: 263mg | Iron: 1.5mg