Being of Cornish decent and having eaten pastie all my life I have just a few suggestions. In addition to potatoes and onions add a small turnip also a little green onion. Also mix potatoes, meat, turnip with a little butter, salt and pepper in a large bowl, before adding to pie crust. Your can also substitute the type of meat, just use a lean meat. Also my mother would eat them hot with just butter, salt and pepper. My grandfather used to do the same but, added hot sauce.....