In a bowl, combine chicken, soy sauces, oyster sauce, sesame oil, cornstarch, and white pepper. Add sliced mushrooms and Chinese sausages. Cover and refrigerate for at least 1 hour, or overnight for more flavor.
Soak rice in water for 20 minutes, then drain and rinse. Add rice and water to a claypot.
Place ginger slices on top of the rice. Cook over medium heat for 5 minutes until water is mostly absorbed.
Arrange the marinated chicken, mushrooms, and sausages on top of the rice. Cover and cook on low heat for 10 minutes.
Drizzle a little neutral oil around the rim of the claypot. Cover and cook for an additional 5 minutes to get a golden, crispy crust.
Drizzle the extra sauce over the top. Garnish with green onions and enjoy straight from the pot!