In a medium Dutch oven with a lid, over medium heat, add the oil. When the oil is hot, sear the ham hocks in batches, until brown, about 4 to 6 minutes. Remove the ham hock and set aside. Add the onions. Season with pepper. Saute for 2 minutes. Stir in the beans and bay leaves. Season with pepper. Saute for 1 minute. Add the reserved ham hocks and water. Bring to a boil and reduce the heat to medium low and simmer for 2 hours, or until the meat falls of the bone and the beans are creamy. Remove the bay leaves and season with salt and pepper.