Just like with my classic breakfast casserole, for the potato breakfast casserole, I use the basics ingredients of eggs, milk, cheese, browned meat (hamburger, turkey, sausage) and cream of (mushroom, celery) soup. Instead of croutons or dried bread, though, I use hash browns.
For a typical breakfast casserole for work or other large group, I use 2 cups of milk, 18 eggs, 2 cans cream soup, 1 package frozen has browns (or 4 or 5 large potatoes grated), 2 cups cheese, 1 lb ground meat.
First I spray the pan with non-stick spray and spread the frozen hash browns.
Then I top that with browned meat and spread cheese over that.
Then I thoroughly mix together the eggs, milk, and cream soup and pour it over the top.
Cover and refrigerate over night. Preheat oven to 375 degrees and cook about an hour until firm in the middle.
To have an extra cheesy casserole, spread and extra cup of cheese over the top about half-way through cooking. This one works well with a spiced up version with fresh jalapeños added into the mix.
The more I have made this variation, the more I have come to prefer it over the bread-based one.