Preheat oven to 325 degrees F.
Mix rice, chestnuts, onion and herbs together. Fill goose with wild rice stuffing, stitch up openings and truss. Place a rack in a large roasting pan, set pan over one or two stove top burners and add enough water to come to just under the rack without touching it. Place goose, breast-side up, on rack and bring water just to a simmer.
Cover pan tightly with a lid or foil and steam goose for 45 minutes. If necessary, remove some the liquid fat as it accumulates in pan, using a bulb baster (be careful of the steam when you uncover the pan) - or add more water. Transfer goose to a platter and pour off fat from the roasting pan (reserve it for another use, if desired).
Sprinkle goose all over with salt and pepper to taste and place, breast-side down, on rack in roasting pan. Roast for one and a quarter hours, then turn goose over. Begin brushing pomegranate juice on goose and continue until it is cooked through.
Roast for 45 minutes to one hour longer, until an instant-read thermometer inserted into the thickest part of the thigh, away from the bone, registers 175 degrees F-180 degrees F.
Remove the goose from the oven, transfer to a cutting board and let it stand, loosely covered with foil, for 15 minutes before carving.
Make gravy by sifting flour into cooking juices and mixing well. Whisk in water and let cook for five or six minutes. Once thick, season with salt and pepper. Serve on the side with the goose.