Cheese and Onion Pie vs Reibekuchen / Kartoffelpuffer (German Potato Pancakes)

Both dishes start from potato, onion and egg, yet treat them in opposite ways. The pie boils and roughly mashes its potatoes, then folds in onions slowly softened and lightly caramelized in butter, strong cheddar and milk for a creamy, savory filling inside buttery shortcrust; egg appears only as a golden glaze on the lid. The pancakes use raw, coarsely grated potato and onion, squeezed dry, bound with egg and a little flour, seasoned with nutmeg and black pepper, and fried until crisp.