Hash Brown Casserole

Preparation

1. Step 1

   Prepare the casserole: Remove the frozen hash browns from the freezer and set aside. Heat the oven to 350 degrees with the rack in the center position.

2. Step 2

   Prepare the cream of chicken soup: In a medium saucepan, melt 3 tablespoons butter over medium. Whisk in 2 tablespoons flour until smooth; repeat with the remaining 2 tablespoons flour. Continuously whisk the butter-flour mixture (known as roux) to cook off the raw scent of the flour, about 1 minute.

3. Step 3

   Slowly pour in the milk, whisking continuously, until thickened, about 1 minute. Slowly pour in the chicken stock, whisking continuously. Add ½ teaspoon salt, ½ teaspoon black pepper, the onion powder, garlic powder and celery salt. Stir continuously, until thickened and the mixture coats the back of a spoon, about 3 minutes. Remove from the heat, taste and adjust seasonings. Set aside to cool slightly.

4. Step 4

   Melt the remaining 8 tablespoons of butter. Grease the bottom of a 9-by-13-inch casserole dish with about 2 tablespoons of the melted butter, swirling it around.

5. Step 5

   To a large bowl, add the rest of the butter, the homemade cream of chicken soup and sour cream and whisk to mix. Add the onion, Parmesan (if using) and two-thirds of the Cheddar. Stir and season with 1 teaspoon each salt and pepper. Add the hash browns, gently breaking them up by hand if they’re still frozen in a solid block. Stir until everything is well combined.

6. Step 6

   Add the hash brown mixture to the casserole dish, spread evenly and top with the remaining Cheddar.

7. Step 7

   Prepare the topping (if using): Toss the crushed cornflakes with the butter and sprinkle on top of the casserole.

8. Step 8

   Bake the casserole uncovered until bubbling at the bottom and beginning to crisp and brown around the edges, about 1 hour. If the optional topping browns too quickly, tent the top with foil. Let sit for 10 minutes, then garnish with parsley if you’d like and serve.