In a large, heavy-bottomed pot with a lid or Dutch oven, heat 2 tablespoons of the duck fat over medium heat. Add the sausage, breaking apart with a wooden spoon. Cook for 5 minutes and add the chopped onion and herbs. Continue to sauté the sausage and onion until the onion is translucent and the herbs are aromatic, about 5 minutes longer.
Add the rice and stir well, coating the rice grains with the sausage, onions and herbs. Cook for about 2 minutes. Turn the heat up to high and add the wine, cooking until completely evaporated. Add the chicken stock or water, season with salt and pepper, and bring to a boil. Immediately turn the heat down to a low simmer, put the lid on the pot and cook for 45 minutes, until the rice is tender.
Meanwhile, heat the remaining tablespoon of duck fat in a small pan over high heat. Add the giblets, liver and hearts and sauté until just browned on one side, then flip and brown the other side. Cool slightly, roughly chop, and set aside.
Once the rice is cooked, allow it to sit for about 10 minutes, then stir in the giblets, etc. Pour the rice into a large baking dish and stir in any caramelized bits from the duck-roasting pan, along with any juices accumulated from the resting duck. Place in the 500° oven (when you glaze the duck) and brown the top, about 10 minutes.