Preheat oven to 300 degrees F (150 degrees C). Grease a 9x13 inch baking pan.
Spread frozen hash browns into the bottom of the prepared pan. Mix together potato soup, celery soup, onion, green bell pepper and sour cream; pour the mixture over the potatoes.
Bake in the preheated 300 degrees F (150 degrees C) oven for 60 minutes. Remove the pan from the oven, sprinkle with cheese, and bake another 30 minutes or until the cheese melts.
