Soak soybeans for 1 hour in water. Drain.
Mash drained soaked soybeans.
In a small saucepan, heat oil. Add ginger and garlic. Saute until softened, about 2 minutes.
Add scallions and cook for 30 seconds.
Add beans and sauté for 1 minute.
Add broth, rice wine, soy sauce, sugar, vinegar and chili. Bring to a boil. Reduce to a simmer and cook for 8-10 minutes, until reduced by half.
In a small bowl, dissolve cornstarch in 1 tablespoon water. Stir to combine. Add to bean sauce and cook for 1 minute, until thickened.
Now that the sauce is done, let’s make the chicken.
Heat peanut oil in a wok or skillet. Add onion, garlic and ginger. Stir fry until they start to change color.
Add mushrooms, chicken and sesame oil. Stir fry until chicken is cooked through, about 5 minutes.
In a small bowl, whisk together the black bean sauce, rice wine and oyster sauce. Whisk until well combined.
Add to skillet and toss to make sure all the chicken pieces are coated with the sauce. Cook for 1 more minute.
To serve, garnish with the scallions.