Depending on how much rice you have left, i would add mozzarella, napolitana sauce and bechamel sauce in layers like you would a lasanga, and bake it in a baking dish that has been buttered on the bottom and side, sprinkle some bread crumbs all over, it makes a nice crunchy crust
i make this using long grain rice. i use napolitana or bolognese sauce, bechamel sauce , peas, hard boiled eggs, mortadella, mozzarella, parmesan cheese and fried eggplant.