According to Salma Hage, from whose cookbook this recipe was adapted, this dish improves dramatically by letting the flavors marry overnight. She also points out that this dish is often considered best when served at room temperature. I found this to be true. The flavors in the dish, particularly the flavor of the slightly caramelized onions, absorb into the rice and make for a wonderful dish when stored overnight in the refrigerator and allowed to warm to room temperature before being served.