To assemble the dish, layer a ½ of the rice at the bottom of a greased oven-proof dish. Drizzle with half of the spiced butter. Next, cover the rice with the chicken curry. Follow with the rest of the rice and the remaining butter. Finally, cover the rice with the fried potatoes and onions (reserve some onions for serving). Pour over the chicken stock and cover with foil (or a lid if your oven-dish has one).