To make spinach casserole, first heat oil in a pan. Add cumin, ginger and cook for 10 seconds. After 10 seconds, add tomatoes, turmeric powder and cook till the tomatoes become soft. After the tomatoes are soft, add spinach and salt. Cover the pan and let it cook until it becomes soft. After the spinach becomes soft, increase the heat and let the spinach water disappear. Now add cooked rice, sambar powder, salt and mix it. Turn down the heat, cover the pan and let it cook for 2 minutes. After 2 minutes, open the pan, mix and turn off the gas. Serve hot. Serve Pulao Pulao with Bundi Raita, Kachumbar Salad and Papad for day or dinner.