Peel the potatoes, cut into chunks, cook in lightly salted water until soft then mash.
Mix with butter, eggs and milk (or milk/cream) to create a fluffy potato mash and season with salt and grated nutmeg.
Spread it onto a buttered baking tray or in a buttered gratin dish. Cut the bacon into strips and insert into the mash. The strips should protrude a little. Spread the butter flakes on top and bake in a preheated oven at 220° until golden brown.