1. Thaw potatoes slightly for easier mixing
2. Mix together sour cream, soup, salt and cheese
3. Add hash browns and mix together
4. In a pan, saute onions in butter until tender
5. Mix onions into sour cream and hash brown mixture
6. Pour into a greased 9x13 glass dish
7. Sprinkle with parmesan cheese
8. Bake at 350 degrees for 1.5 hours
