I found this in with a box of old hand written recipe cards & magazine clippings I purchased at a thrift shop in Kansas. Everyone grabbbed for seconds after we first tried this. You may use reduced fat ingredients if you must, but the fat free versions will not provide enough flavor. I usually use lower fat sour cream & cottage cheese, but full fat NY Cheddar for the topping. If you like, you may freeze the casserole before baking, then cook it at 400 F for 1 hour instead.