Toss flour, butter and 2 tsp fine sea salt in a bowl to combine and place in the freezer for 10 minutes to chill.
Combine 140ml iced water and vinegar in a jug, then place in the freezer to keep chilled.
Remove bowl from freezer. Tip ingredients out onto a work surface, then rub butter into flour with your fingertips until most of the butter remains in large lumps. Bring together with your hands, then with the heel of your hand, push and smear the dough away from you.
Drizzle over iced water mixture and continue to push and smear dough until it starts to come together. Bring dough together and gently knead. Divide in half, form into discs, wrap in plastic wrap and refrigerate overnight to rest.
To roll out, stand pastry at room temperature for 15-20 minutes until pliable, then place one pastry disc on a lightly floured piece of baking paper and roll to a rough 4mm-thick, 36cm-diameter round. Using the baking paper, slide onto a flat tray, cover with another piece of baking paper and set aside. Repeat with remaining pastry disc, transfer to tray, cover tightly with plastic wrap and refrigerate until required.
