The ultimate in comfort food! This is my daughter, Anna Claire's favorite recipe. We always have it for holidays, birthdays and other special occasions. It is definitely NOT figure friendly and is just not very good if you substitute fat-free ingredients. So, just go for it!
In a colander, thaw the frozen hash browns. Preheat oven to 350 degrees.
In a medium saucepan, cook chopped onions in butter until translucent. Add undiluted soup, sour cream and 2 c. of the cheese into saucepan. Continue stirring over medium heat until smooth. Remove from heat.
Put thawed potatoes into a large mixing bowl. Pour sauce over potatoes and mix until thoroughly coated. Pour into large greased casserole dish. Top with the rest of the cheese.
Bake at 350 degrees for 35-40 minutes until golden and bubbly.