Instructions

1. 1
   Peel and slice your potatoes very thin.
2. 2
   Layer the potatoes in a pie dish, adding some onion, salt, and pepper between each layer.
3. 3
   Add a dash of water to the potatoes, and scatter the chopped butter over top.
4. 4
   Cover the filling with the rolled-out puff pastry.
5. 5
   Bake at 375°F until golden and cooked through (about 1½ hours).