Hashbrown Casserole with Cornflakes

Hashbrown Casserole with Cornflakes:
Mel's Kitchen Cafe

3 Tablespoons butter
1 large yellow onion, chopped
1/4 cup all purpose flour
1 1/2 cups chicken broth
1 cup milk
1 1/2 teaspoons salt
1/2 teaspoon pepper
1/2 teaspoon dried thyme
2 cups shredded sharp cheddar
28 oz bag frozen shredded hash browns
1/2 cup sour cream

Topping:
3 cups cornflakes, lightly crushed
2 Tablespoons melted butter

Melt the butter in a large pot over medium heat.  Add the onion and cook until onion is softened and translucent (about 5-6 minutes).  Stir in the flour and cook, stirring constantly for about a minute.  Combine the chicken broth and milk in a liquid measure and slowly whisk in the mixture.  Add the salt, pepper and thyme.  Stir to combine.  Bring the mixture to a boil and then reduce the heat to medium-low and simmer, stirring frequently, until the mixture is slightly thickened (about 5 minutes).

Take the pot off the heat and stir in the cheese until smooth.  Mix in the frozen hash browns until well combined.  Finally stir in the sour cream.

In a medium bowl, toss the lightly crushed cornflakes with the melted butter until evenly combined.  Scoop out the potato mixture into a 9x13 inch dish and top with the buttered cornflakes.

Bake at 350 degrees for 45 minutes.

Note:  Can prepare ahead up until the cornflakes.