
In a bowl, toss the cubed chicken with cornstarch until evenly coated.
Heat oil in a wok or skillet over medium-high heat. Add ginger and stir-fry until fragrant. Add the chicken and cook, stirring, until the surface turns opaque.
Add chestnuts and shiitake mushrooms. Stir to combine with the chicken.
Pour in soy sauce, oyster sauce, dark soy sauce, Shaoxing wine, sugar, and water. Stir well, then lower the heat. Let it simmer gently until the sauce thickens and the chicken is cooked through.
Add scallions, give everything a final stir, and dish out. Serve hot.