Soak the oatmeal in 2 cups of broth overnight refrigerated.
Combine the chicken, Shaoxing wine, salt and potato starch in a medium-sized bowl. Mix well until the chicken is evenly coated. Set aside to marinate for at least 10 minutes..
In a sauce pan add the remaining broth to the overnight oats, salt and pepper, sliced mushrooms and ginger slices. Bring the pot to a boil and simmer for 15-20 minutes, stirring frequently until the porridge starts to thicken.
Add the marinated chicken pieces, stir constantly to separate the chicken pieces. Cook until the chicken just turns opaque, no more than 5 minutes or so. If the congee is too thick add a little water to thin out. Add the baby spinach if using, the spinach will wilt with heat. Stir to mix well. Taste the congee and add more salt if needed.
Serve garnished with chopped green onions, chili crisp if desired, toasted sesame seeds.