This is a simple comfort-food type casserole. I highly recommend using Panko breadcrumbs, as they provide the most crunch, but you could also used crushed Ritz crackers.
I used Southern style hashbrowns, which are the diced variety vs. shredded. You can use either variety.
If you don't have celery seed, you can replace one of the soups with cream of celery and get pretty much the same flavor.
CHICKEN BROCCOLI HASHBROWN CASSEROLE
2 lbs. frozen hash brown potatoes, thawed
3 cups diced cooked chicken breast
1 (12 oz) package frozen broccoli florets
1 can cream of mushroom soup
1 can cream of chicken soup
1/2 cup milk
1 cup sour cream
3 Tbsp. dried minced onion
1 tsp. garlic powder
1/2 tsp. ground black pepper
1 tsp. celery seed
2 cups shredded cheddar cheese, divided
2 Tbsp. butter, melted
1 cup breadcrumbs
Preheat oven to 400 degrees. Lightly grease a 13x9 glass baking dish.
Microwave broccoli according to package directions. Drain.
In a large bowl, combine soups, milk, sour cream, minced onion, garlic powder, black pepper, celery seed, and 1 cup cheddar. Fold in potatoes, chicken, and broccoli. Pour into baking dish and sprinkle remaining cheddar on top.
In a medium bowl, combine melted butter and breadcrumbs. Sprinkle over casserole.
Bake for 35-40 minutes or until hot and bubbly.