I have a question about the recipe "Potato Leek Tart with Goat Cheese and Parsley Purée" from artandlemons. This recipe looks amazing but I am having some difficulty understanding the directions. First, should the potatoes be precooked or not? They will cook with the leeks. Second, where does the potato and parsley minxtue come into the layering process before baking the tart? I have read the instructions three times and seem to be missing it. Any thoughts?