Puff pastry

1.Form butter on a surface into a 14cm square slab (if using 250gm blocks, halve the blocks lengthways, place next to each other, then bash out with a rolling pin). Chill until ready to use.

2.Tip flour and 2 tsp cooking salt onto a work surface, make a well in the centre, and place vinegar, melted butter and 200ml water in the well. Using your fingertips, work wet ingredients into the dry, while pushing small quantities of flour into the well with your other hand until all incorporated, then lightly knead the mixture until a smooth, firm dough forms, called a détrempe (about 5 minutes). Roll dough into a ball and cut a cross on the top. Wrap in plastic wrap and refrigerate to rest for 2-3 hours. Remove détrempe from the fridge 1 hour before rolling and butter about 30 minutes beforehand.

3.Place détrempe on a lightly floured surface, then roll out from each corner of the cross to form a four-pointed star shape, leaving a small mound of dough in the centre. Brush off excess flour as you go.

4.Put the butter slab in centre of détrempe. Give it a few whacks with a rolling pin to get rid of air pockets and get the two elements associated, then fold the four points of dough over to enclose butter, brushing off excess flour as you go. Press to seal, wrap in plastic wrap, and refrigerate so détrempe and butter have the same temperature (30 minutes).

5.Remove dough from refrigerator and stand at room temperature for 10 minutes. Lightly dust a work surface with flour. Whack along dough with a rolling pin to make even and malleable and easier to roll. Keeping the top and bottom layers of the détrempe the same size as the butter inside, roll the dough away from you to form a rectangle (70cm x 40cm). Mark the dough into 3 equal parts. Fold the third closest to you towards the centre, brush off flour, then fold the top third over the centre and brush off flour. This is called the first turn. Turn the rectangle 90 degrees clockwise. Repeat rolling dough gently away from you, flouring the work surface as you go, to form a rectangle (70cm x 40cm). Fold the dough once more into 3 equal parts. This is the second turn. Wrap in plastic wrap and refrigerate (30 minutes).

6.Give the dough 2 more turns, then wrap in plastic wrap and chill again (30 minutes to 1 hour).

7.After chilling, give the dough 2 more turns, making it 6 in total. Wrap in plastic and chill again before rolling out according to the recipe.