01 -
Preheat oven to 350°F. Grease a 9 x 13-inch baking dish with unsalted butter or non-stick spray and set aside.
02 -
In a small bowl, combine shredded cheddar and Monterey Jack cheese. Toss to mix thoroughly. Set aside.
03 -
Place thawed hash brown potatoes in a large bowl. Add 4 tablespoons melted butter, 1/2 teaspoon salt, and 1/2 teaspoon black pepper. Toss until potatoes are evenly coated.
04 -
Fold in sour cream and 2 cups of the combined shredded cheese mixture. Mix gently until fully integrated. Reserve the remaining cheese for layering.
05 -
Melt 4 tablespoons butter in a large skillet over medium heat. Sauté diced onion until translucent, about 4–5 minutes. Add minced garlic and cook 1 minute, stirring constantly.
06 -
Sprinkle flour over the onion mixture. Cook, stirring frequently, for 1 minute. Gradually whisk in the chicken broth, ensuring a smooth consistency. Continue whisking in the milk until the sauce is well blended. Bring to a gentle simmer, season with salt and pepper, and cook for 3–4 minutes until slightly thickened. Remove from heat.
07 -
Pour the warm cream sauce over the potato mixture. Gently fold together with a spatula to fully incorporate. Transfer the mixture into the prepared baking dish and spread evenly.
08 -
Sprinkle the remaining cheese evenly over the top of the potato mixture.
09 -
In a medium bowl, combine crushed cornflakes and 4 tablespoons melted butter. Toss until the cornflakes are thoroughly coated.
10 -
Distribute the buttered cornflake topping evenly over the cheese layer. Cover the dish with aluminum foil and bake for 20 minutes. Remove foil and continue baking for 15–20 minutes until the edges are bubbling and the topping is golden brown.
11 -
Allow to rest for 10 minutes before serving to set and enhance flavor.