01 -
Put the flour and salt together in a bowl and give it a mix. Toss in small cubes of the cold butter, without mixing them in too much.
02 -
Pour in most of the chilled water, stirring with a dull knife until it starts to stick together. Add a bit more water only if needed, but avoid making it sticky.
03 -
Dust your surface with flour, roll the dough into a rectangular shape, and fold the top and bottom thirds like an envelope. Turn it sideways and repeat the process two more times.
04 -
Wrap the dough tightly in plastic wrap and pop it in the fridge for 30 minutes.
05 -
Set your oven to 200°C (400°F) and get a baking sheet ready with parchment paper.
06 -
Bring salted water to a boil. Use a mandoline slicer to cut the potatoes into thin rounds (1 mm). Blanch them briefly for 30 seconds, then cool them off in iced water and drain well.
07 -
Roll the chilled dough into a rectangle about 48 cm long and 15 cm wide. Trim the edges neatly and cut it into 6 smaller rectangles.
08 -
Score a line about 3/4 cm away from the edge of each rectangle, then poke tiny holes in the middle. Spread them out on the lined baking tray.
09 -
Cut the brie into thin slices and place them inside the scored area of each pastry. Add overlapping slices of potato (6-8 rounds) on top. Brush the potato slices with olive oil, and give the pastry borders a coat of beaten egg.
10 -
Scatter parmesan over each tart and bake for 20-25 minutes until crisp and golden. Sprinkle fresh, chopped rosemary and a small pinch of sea salt before serving up.