Ultra Cheesy Hash Brown Casserole

INGREDIENTS

1/4 cup

butter

1/2 cup

finely chopped onion

1 can

Campbell's condensed cream of chicken soup

2 cups

shredded cheddar cheese

1 cup

sour cream

1 tsp

kosher salt

1/4 tsp

freshly cracked black pepper

1 lb

bag of frozen shredded hash brown potatoes , slightly thawed