Boil the rice in salted water for about 12 minutes (the water must be completely absorbed), then add the butter into small pieces, stir and pour the rice on a tray. Let the rice cool for a couple of hours, covering it with the film to prevent it from drying. Add the chopped parsley, the Parmigiano Reggiano, the egg, the chili pepper and ground pepper. Mix everything and form the rice balls rolling them between your hands to make them round. Roll them in breadcrumbs and fry them in sunflower oil. Once cooked, place them on a plate with some absorbent paper and serve hot.