Add the salt to the water and stir to dissolve.

Mix both flours together in a mixing bowl.

Cut the butter into cubes about the size of shelled hazelnuts.Add the butter cubes to the dry ingredients and toss to coat and separate all the pieces. Pour the salt water in to the butter/flour mixture and gently mix until a dough ball forms and all the dry ingredients are incorporated.  Do not over mix or you will toughen the dough and mix the butter in to the dough too much; you still want to see the chunks of butter.  I prefer to do the mixing by hand. Wrap the dough in plastic wrap and put in the fridge for 20 minutes.

Sprinkle a light layer of bread flour on to the surface where you will be rolling out your dough.  Remove your dough from the fridge and put on the floured surface.  Sprinkle some more of the flour on to the dough itself to keep your rolling pin from sticking.  Roll your dough out in to an approximate rectangle about 1” thick.  Don’t worry if it looks like a mess, that’s normal and it will look a lot better when you are done.      Now you are going to make a “book-fold”; fold the opposite short side edges of your dough into the middle so they almost touch (leave about an inch of separation between the edges). Brush away any loose flour that sticks to the dough, if you don’t it will prevent the dough from sticking to itself as you fold it together.Now fold the dough in half along this separation as if you are closing a book.  You should have a 4-layer stack of dough.Repeat this process 2 more times, make sure that the “spine” of the book is to your left each time you roll out your rectangle.Tightly wrap your finished puff dough and put back in the fridge to cool down.  If you don’t plan on using it right away, it can be kept chilled for up to a week or frozen for up to 3 months.