Step 1

Preheat over to 350° Fahrenheit. Spray 9x13 baking dish with non stick cooking spray.

Step 2

In a glass bowl, toss 2 C of the cheese and all of the potatoes together. Evenly fill 9 x13 dish with cheese & potatoes.

Step 3

Pour melted butter over the top of the cheese & potatoes.

Step 4

In same glass bowl used for the cheese & potatoes, whisk together sour cream, broth, onion powder, salt & pepper. Heat in microwave for 2 minutes. Whisk in 3 Tbsp flour until smooth. Pour sour cream mixture evenly over potatoes and cheese.

Step 5

Top with remaining 1/4 C grated cheddar and additional black pepper.

Step 6

Bake until cheese is melted and edges of casserole is bubbling, about 45 minutes. Remove from oven and top with parsley or chives, if desired.