Partially thaw the puff pastry dough in the refrigerator or at the room temperature.

Preheat the oven to 200°C

To make a sachet, tie the thyme, garlic, bay leaf, peppercorns, and chilli flakes in a piece of cheesecloth.

Place the potatoes in a saucepan and cover with cold water. Season the water with salt and add the sachet.

Bring to a simmer and cook until the potatoes are tender, about 35 minutes.

Drain off the water, discard the sachet, and allow the potatoes to rest for 5 minutes, letting the moisture steam off.

Mash the potatoes with a fork and stir in the olive oil. Beat one of the eggs and stir it in.

Mix in the marjoram, thyme, and rosemary, and season with salt to taste.

To make the top of the pastry case, place one of the pastry sheets on a parchment paper-lined baking sheet.

Beat the remaining egg and brush the puff-pastry with it.

Place a wire rack directly on top of the dough to allow it to rise only about 3/4 inch as it bakes and bake in the oven for 12 to 15 minutes until puffed and golden brown.

Lower the oven temperature to 180°C

To make the base, place the second pastry between 2 sheets of parchment paper

Place on a baking sheet and top with a second baking sheet to keep the pastry from rising too much as it bakes. Bake until light golden brown, about 30 minutes.

Lower the oven temperature to 160°C

Place a straight-sided tart mold around the baked pastry base on the baking sheet.

Fill the mold with the potato mixture and bake in the oven until the potatoes are set, about 30 minutes

Brush the bottom of the top pastry case with egg wash and place on the potatoes.

Bake in the oven until set, 12 to 15 minutes.

Cool for a few minutes at room temperature and then gentle remove the mold.