Leave the flours in warm place overnight if that's possible.
Pre heat the oven to 200°C, gas 7.
Put the warm flour into a mixing bowl on a machine, add the salt, and olive oil, and then mix well.
Next, add the yeast with ¾ of the water and ½ teaspoon of castor sugar.
Add the laverbread to the flour, and mix for a minute or so.
Mix well and then add the vinegar and the rest of the warm water until you end up with soft dough.
Either knead in the machine or by hand for a good 4-5 minutes. It should be free from stickiness and leave the edges of the bowl.
Place the dough back in the bowl and cover with cling film.
Leave to prove in a warm place until the dough has doubled in size. This will take 25 minutes, approximately.
When the dough is ready, turn out onto a lightly floured surface and gently "knock back" this means to re knead. But don’t go mad, you just need to re form lightly for 1-15 seconds that’s all. Do not go mad, just massage out the air ready for moulding.
Mould into a flattened loaf shape, making sure that the folds are underneath.
Pop into a greased 2lb loaf tin, Dust with flour, cover with film and prove again to just under double the size.
Carefully remove the cling film then, slash the loaf top, right down the middle, with a very sharp knife or a razor is the best for this.
Place in the hot oven.
Bake the bread until the crust is nicely browned, then take the loaf out of the tin, place it back in the directly on the bars or on a small wire rack on a baking sheet.
This will allow the crust to develop all around the loaf.
When the loaf is cooked remove from the oven and cool on a wire rack.
Leave to cool completely before attempting to cut.