Combine the chicken, garlic, ginger, soy sauce, dark soy sauce, oyster sauce, sugar, corn starch, and salt in a bowl and mix well. Let it marinate for 15 minutes.

Stir together the soy sauce, oyster sauce, sugar, and water to make the sweet soy sauce, then set aside.

Wash and drain the jasmine rice completely. Add the rice and water to the claypot and bring to a low boil over medium heat. Once boiling, lower the heat to medium low and cook for 3 minutes until the water is absorbed.

Layer the chicken, Chinese sausage, and shiitake mushrooms on top of the rice, leaving some space in the middle for the egg later. Cover, drizzle 1 tablespoon avocado oil around the edge of the lid, and cook for 5 minutes. Drizzle another 1 tablespoon avocado oil around the edge, then rotate the claypot to heat all four sides for 4-5 minutes so the edges get crispy. Partway through, drizzle the final 1 tablespoon avocado oil around the edge to ensure you get a crispy rice bottom.

Turn off the heat, crack the egg on top of the rice, cover, and let sit for 2-3 minutes until the egg is slightly cooked with a runny yolk.

Garnish with a dash of white pepper, chopped scallions, and a drizzle of sweet soy sauce. Mix the rice and scrape up the crispy bottom, then serve immediately.