Ice-in-Heaven is a delicious dessert that is easy to make. Dissolve starch well in cold water and dissolve rice-flour well in cold milk. Mix the two solutions and bring to slow boil over low heat. Regularly stir the mix until it thickens. Now add sugar and rosewater. Continue stirring the mix while it boils very slowly so that it does not settle.
When the mix becomes very thick, it is ready. Pour it into a deep rectangular dish and shake so that the surface is level. Let it cool down completely in the refrigerator, then cut a grid into it the lines of which are parallel to the diagonals of the dish. Sprinkle the pistachios on top and serve.