To prepare the fish, pat the fish dry well with paper towels to remove excess moisture, then use a knife to make 4–5 diagonal cuts on each side without cutting all the way through. In a bowl, add the fish with the ginger, scallions, rice wine, and salt, then gently rub to coat and let it sit for 5 minutes. Remove the ginger and scallions, then lightly coat the fish with cornstarch.
To make the sauce, in a bowl, mix the soy sauce, dark soy sauce, Chinkiang vinegar, sugar, and white pepper until combined.
To pan-fry the fish, in a wok over medium heat, add the cooking oil, then carefully add the fish. Let it cook undisturbed for about 3 minutes until lightly golden, then gently turn and cook the other side for another 3 minutes. Remove the fish.
To build the braising base, in the same wok over medium-low heat, add the cooking oil if needed, then add the ginger, garlic, and scallions (white part), and stir-fry until fragrant. Add the Pixian bean paste and stir-fry gently until the oil turns slightly red and aromatic.
To braise and finish, pour in the sauce and water, then stir gently to combine. Return the fish to the wok, cover, and simmer over medium-low heat for 5 minutes. Uncover, raise the heat to high, and reduce the sauce for about 1 minute until slightly thickened. Add the red finger hot pepper and scallions (green part), then spoon the sauce over the fish and serve immediately.