Rinse peas with cold water and pick out any stones or bad peas. Soak in warm water for 35 minutes. Drain and set aside.
Combine ham hocks and water. Boil for two hours and 45 minutes. Add peas, onion, black pepper, and thyme. Cook for 45 minutes to an hour, or until tender. Add rice, stir, and simmer over medium heat for 20 to 25 minutes or until rice is tender.