1. Add flour, salt and butter in a mixing bowl. Mix until well combined and a sand-like consistency.
2. Warm milk, water and sugar (about 35 degrees). Remove from heat and dissolve dry yeast. Set aside for 5 minutes to thicken and activate..
3. Add wet to dry and mix until a smooth dough is formed.
4. Wrap well in cling film and leave at room temp about ½ hour to start the rising process. Transfer to the fridge overnight between 12 - 24 hours (a stronger flavour will develop the longer in the fridge).
5. In the meantime, use a rolling pin to shape the 300gm butter in between sheets of baking paper into a square about 1cm thick. Keep in the fridge.
1. Pull the butter square out of the fridge to soften slightly.
2. Roll out dough into a square slightly larger than your block of butter.
3. Place butter in the center of the dough and fold the edges over to completely and evenly cover. Stat lamination.
4. Roll the pastry block out completing 4 book turns. Refrigerate between each turn to rest the gluten. The dough won't stretch if it's overworked.
5. Wrap well and refrigerate.