Gently simmer the rice in 5 to 6 cups of lightly salted water until firm tender, about 30 minutes. Drain well and place in a bowl; mix in the remaining ingredients, except the stock and pomegranate seeds. Preheat the oven to 350 degrees F. Spoon the rice mixture into a lightly buttered, shallow-sided casserole. Pour in the stock. Cover and bake 30 minutes. Uncover and stir in the pomegranate seeds. Cover and bake 5 minutes more, and then serve.