Dauphinoise Potatoes

Thinly slice the potatoes lengthwise, toss with 40g of salt
Add cream, milk and truffle paste to a big pan and bring to 85 degrees
Remove from the heat and add sliced potatoes
In a tray lined with baking parchment, lay the potato slices flat ensuring they are in even layers
Add all of the cream mixture that you can to the tray before placing baking parchment on top and foiling it tightly
Cook in the oven at 160c for 105 minutes, until a knife slides easily through the cooked potatoes
Place another tray on top and a weight to press it down while chilling

Spinach filling

Thinly slice the onions and cook down in butter until they are soft and well caramelized
Chop the pancetta and fry it until crispy
Wilt down the spinach, then drain and squeeze out all the liquid
Mix onions, pancetta and spinach and chill

Pie pastry

Cut a 110cm x 110cm piece of pastry for the bottom layer
Cut a 150cm x 150cm piece of pastry for the top layer

Truffle Pancetta and dauphinoise pie

Place dauphinoise + spinach filling on top of the bottom layer of pastry, brush around it with egg yolk to seal later
Cover it with the top layer of pastry, carefully molding it so that it covers all of the filling and making sure there are no crimps
Press down on the pastry making sure that top and bottom layers are sealed together, then cut it with an appropriate sized ring cutter
Bush all over the pie with egg yolks, make a vent hole on the top and decorate the sides with patterns made with the tip of a knife
Bake at 185C for 15 minutes, until pastry is golden brown.