Potato-crusted saffron rice

A gently sweetened rice and potato bake perfumed with saffron, though it’s fried really, not baked, until crisp and golden. Use a mandoline to slice the potatoes as they need to be exactly the same thickness for even cooking. The saffron sugar syrup will continue to develop flavour and colour over a period of seven days so begin this step up to a week in advance.