5 from 9 votes
Au Gratin Hash Brown Casserole
These Au Gratin Hash Brown Potatoes are the definition of comfort food! Like a loaded baked potato in casserole form! Perfect for parties and holidays.
Prep Time
15 mins
Cook Time
1 hr
Total Time
1 hr 15 mins
Servings:
12
Course:
Side Dish
Cuisine:
American
Ingredients
- 1 (30 oz) hash brown potatoes thawed, frozen, shredded, packaged
- 4 Tbsp butter diced into 1 Tbsp pieces
- 1/2 cup yellow onion finely chopped
- 1/4 cup all-purpose flour
- 2 3/4 cups milk (whole or 2%)
- 1 1/2 cups cheddar cheese shredded sharp
- 1/2 cup Parmesan Cheese finely shredded
- 1 cup sour cream
- salt freshly ground
- black pepper freshly ground
- 4 cups cornflakes crushed (nearly 2 cups once crushed
- 3 Tbsp butter melted
- 1 1/2 Tbsp parsley chopped, fresh
Instructions
- Preheat oven to 350 degrees.
- Melt 4 Tbsp butter in a large saucepan over medium heat. Add onion and saute until softened, about 5 - 6 minutes.
- Add in flour and cook stirring constantly, 1 minute. While whisking pour in milk then cook stirring constantly until mixture comes to a boil.
- Remove from heat, add in cheddar cheese and parmesan cheese and stir until melted.
- Stir in sour cream. Season mixture with salt and pepper to taste (you want it on the salty side as it will be seasoning the potatoes).
- Place hash browns in a large mixing bowl then pour in milk mixture and toss to evenly coat. Transfer to a 13 by 9-inch baking dish (no need to grease dish) and spread into and even layer.
- Place cornflakes in a gallon size resealable bag, seal bag and crush with a rolling pin to roughly pebble size bits.
- Add 3 Tbsp melted butter to cornflake mixture then seal bag and toss to evenly coat with butter. Sprinkle cornflake mixture evenly over casserole.
- Bake in preheated oven until hot throughout, about 40 - 50 minutes. Garnish with parsley and serve warm.
- Recipe source: Cooking Classy
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