Step 1In a medium bowl, whisk together the pomegranate molasses, honey, ground coriander, cinnamon, allspice, nutmeg, black pepper, ginger, crushed garlic and one-half teaspoon salt.
Step 2Rinse the chicken and pat dry. Place the chicken in a glass or non-reactive bowl and rub marinade into the skin and inner cavity, then pour over any remaining marinade. Cover and chill overnight.
Step 1Place the rice in a wire mesh strainer and rinse under running water. Drain. Heat a heavy-bottom pot over medium-high heat until hot and add 3 tablespoons of oil. Stir in the rice and saute, stirring constantly, about 2 minutes to coat and lightly toast the rice (the rice will not brown, but the edges of the rice should be lightly translucent).
Step 2Stir in the cinnamon sticks, 5 1/4 cups water and a scant teaspoon salt and bring to a boil over high heat. Reduce the heat, cover and cook at a gentle simmer until the rise is almost done and the liquid is mostly evaporated, about 30 minutes. Remove from heat and set aside, covered, for 10 minutes. Fluff with a fork.
Step 3Heat the oven to 350 degrees. Remove the chicken from the refrigerator to temper slightly while you finish the rice.
Step 4Heat a large frying pan over medium heat until hot. Add the remaining 2 tablespoons oil, then the onion and saute until golden brown, stirring frequently, about 8 minutes. Remove from heat. Add the rice, herbs and grapes, stirring quickly with a fork. Remove the cinnamon sticks and season to taste with salt and pepper.
Step 5Remove the chicken from the marinade, saving the marinade. Stuff the chicken with 1 1/2 cups of the rice mixture, and truss.
Step 6Place the chicken in a Dutch oven, and pour over the marinade and the cup of boiling water. Cover and bake for 1 hour, basting occasionally. Remove the cover and continue to roast until the chicken is golden brown and a thermometer inserted in the meat and stuffing reaches 165 degrees, basting often, about 30 minutes.
Step 7Rewarm the rice as needed in the oven, or on the stove top. Transfer the rice to a large serving platter. Place the chicken on the rice and spoon over the liquids remaining in the pot. Serve immediately.