Dice the potatoes into small cubes.

Cook the potatoes (I boiled them in hot water for about 10 minutes, but you can also cook them in a pan).

Heat the olive oil in a pan and sauté the onion and diced smoked bacon until golden.

Add salt and rosemary to the bacon and mix well.

Line a 10-inch (26 cm) pie pan with parchment paper and place the puff pastry on top.

Pour in the potatoes, bacon, and onion, spreading them evenly.

Add dollops of cheese on top (I used truffle brie).

Bake at 350°F (180°C) for about 30 minutes.