Place the oil, gizzards, pork and bay leaves in a large, heavy skillet, preferably nonstick, over high heat and stir well. Cook, stirring occasionally, until the meat is thoroughly browned, about 7 to 10 minutes. Stir in the Poultry Magic®, mustard and cumin, then add the onions, celery, bell peppers and garlic. Stir thoroughly, scraping the skillet bottom well, and add the butter and stir until melted. Reduce the heat to medium and cook, stirring constantly and scraping the skillet bottom well, for 4 minutes. Add the rice and cook, constantly stirring and scraping the skillet bottom, for 4 minutes, when the rice should start to crackle and pop.
Add the stock and stir to loosen any bits stuck to the bottom of the skillet, then cook over high heat, stirring occasionally, for 4 minutes. Stir in the chicken livers, cover the skillet, and reduce the heat to very low.
Cook for 10 minutes, remove from the heat, and leave covered until the rice is tender, about 10 minutes. (The rice is finished this way to preserve the delicate flavor of the livers by not overcooking them.) Remove the bay leaves and serve immediately.