Outstanding recipe! I didn't have any zucchini but had a 250g block of frozen spinach so used that (thawed and juice squeezed out). Using the prosciutto rather than pastry is a great and tasty way to make a tart/quiche different. The only thing I will do different next time will be to cover the top with foil so that the prosciutto doesn't curl. I served this warm with a salad but it would also be great picnic food. Thanks for the recipe!