1. For stage 1. Mix the flours and butter together in a bowl until the pastry comes together in a ball. Flatten the pastry into a disc 2cm (¾ in) thick. Wrap cling film and refrigerate for 2 hours.
2. For stage 2, mix the water, vinegar, and salt together in a bowl. Mix the flours and butter together, sprinkle over the water and mix well. Depending on how much water the flours absorb, you may not need to use all the water. The dough should be soft but not too soft.
3. Using a rolling pin, flatten the stage-2 dough (the détrempe) into a square that is 2cm (¾in) thick. Wrap it in plastic wrap and refrigerate for about 2 hours.
4. Flour the ball of pastry made in stage 1. Roll out on floured baking parchment into a circle 1 cm (½in) thick.
5. Place the square détrempe in the centre of the pastry circle. Fold in all the sides of the pastry taking care the seams meet and the square of the détrempe is completely enclosed.
6. Pat the top of the parcel all over with your fist to spread it out. Then, using a floured rolling pin, roll it out from the centre into a rectangle 3 times as long as it is wide. Be careful not to squash the edges of the pastry.
7. Fold the top quarter of the pastry down to the middle of the rectangle, then fold the bottom quarter up to the middle, edge to edge with the top quarter.
8. Fold the dough in half at the centre. There will be 4 layers of dough. This gives you 'tour portefeuille' and also called a 'double turn'. Flatten slightly. Wrap in cling film and refrigerate for an hour.
9. Place the pastry on a floured work surface with the fold lying to the left. Flatten the pastry again with your fist, then roll out to make a rectangle 3 times as long as it is wide. Fold the pastry as before into the 'tour portefeuille'. Brush off any excess flour, wrap in cling film, and refrigerate for an hour.
10. The last turn, called the 'tour simple' or 'single turn', is made when about to use the pastry. With the folded side on your left, roll the pastry out into a rectangle as before. Fold one narrow end to the middle and the other back over the top of it to make a square. Wrap in cling film and refrigerate for 30 minutes.
Rolling out and baking pâte feuilletée
Make sure the pastry is well chilled before rolling out. When rolling out, use the short, sharp strokes in the same direction. Firmly push in a direction away from yourself in order to extend the pastry. Do not roll backwards and forwards haphazardly or the layers will not rise evenly.
1. Rolling out the pastry on a floured work surface until it is 2-3mm (1/16 to 1/8 thick) thick. From time to time, lift the pastry off the work surface by sliding your hands underneath. It is essential to do this as it will prevent the pastry from overstretching and then shrinking as it cooks. Brush off the excess flour.
2. Cover a baking tray with moistened baking parchment, then slide the pastry onto the paper. Prick all over with a fork. Leave to rest for 1-2 hours in the fridge. Preheat the oven to 200C (400C, gas 6). Bake for 15-20 minutes, reducing the temperature to 190C (375F, gas 5) as soon as the pastry goes in.
Chef's tips
When you cut the pâte feuilletée into a rectangle or a disc, there are always some trimmings left. Do not knead them together, but place one on top of the other, press them down firmly, then roll out. Use to make sweet or savoury mini bouchees ('puffs' or vol-au-vents)
The baking parchment needs to be moistened with water when baking pâte feuillette. This moistening helps to stop the pastry shrinking as it bakes.