Preheat the oven to 375°. In a large enameled cast-iron casserole, heat the olive oil. Add the onion, cinnamon and saffron and cook over moderate heat, stirring, until the onion is softened but not browned, about 5 minutes. Add the rice and stir for 1 minute to coat the rice with the oil. Add the chicken stock, salt and a pinch of pepper and bring to a boil over high heat. Simmer for 2 minutes, stirring occasionally. Cover, transfer to the oven and bake for 15 minutes. Remove the casserole from the oven and let stand, covered, for up to 30 minutes. Fluff the rice with a fork before serving.
Notes: ONE SERVING: Calories 221 kcal, Total Fat 6 gm, Saturated Fat 1 gm