If freezing this casserole prior to serving ,freeze the cheese in a separate bag. Then thaw both bags. Just before you are ready to put the egg mixture into the dish, dump the cheese in and mix it up in the zip lock, then put it all into the dish.
Freezer Hash Brown Casserole" from REALMOMKITCHEN.BLOGSPOT.COM"
4 C. hash brown potatoes
12 oz. evaporated milk
2 C. shredded cheddar cheese
1 tsp. salt
1 C. diced Onion
½ t pepper
1 ½ C. diced green Pepper (or red and green)
1/8 tsp. cayenne pepper
1 C. diced ham
Mix eggs and milk together in a bowl. Add eggs and the remaining of the above ingredients into a one gallon freezer zip lock bag and seal the bag, removing all excess air and freeze. (See tip about the cheese up top) To serve thaw completely in refrigerator and put into a greased 9 x 13 dish. Bake uncovered in 350 degree oven for 45-50 minutes or until a knife inserted comes clean.