Macaroni Pie (Mac-n-Cheese)

A take off the Scottish Macaroni Pie - this is mac-n-cheese with a British twist, all encased in a shortcrust pastry case and topped with freshly grated Parnesan.
This pie comes frozen, ready for you to bake in the oven for a freshly cooked Mac-n-Cheese Pie in about 30 minutes.