Before cooking, wash the fish thoroughly and drain. Place the fish in a mesh colander at room temperature for 30 minutes to 1 hour, until completely dry. (Or dry by pressing the fish with a paper towel).
Place a quarter of the green onions on a plate large enough to hold the entire fish. The green onions will hold the fish so it won’t stick to the plate when cooked.
Stuff ginger slices and a quarter of the green onions (white part) into the cavity of the fish. Rub both sides of the fish with sesame oil. Cover the fish with another quarter of the green onions. Pour Shaoxing wine over the fish.
In a large, deep skillet (or steamer or wok), add half an inch of water and place a steaming basket upside down (or heat resistant colander or strainer) in the middle (see footnote 3). Cover and bring water to a boil over high heat. Carefully place the plate holding the fish onto the steaming basket, cover and steam over high heat for 5 to 8 minutes, until you can easily pull the flesh from the bone with a fork. Stop heat immediately. Carefully use a spatula to transfer the fish to another large plate. Use chopsticks to remove the ginger and green onion from inside and above the fish, and discard the used ginger and onion.
Spread the remaining ginger strips and green onions on top of the fish and set aside. Make sure the seasoned soy sauce is ready beside the fish.
In a wok or small skillet, heat oil over medium high heat. When the oil is warm, break chili peppers and add them, with the Sichuan peppercorns, into the oil. Stir with a spatula until fragrant, about 40 seconds. Turn to lowest heat, carefully use a ladle to scoop out the chili pepper and peppercorn, and discard them. Immediately use a ladle to drizzle the hot oil over the fish. You should hear the sizzling of the oil when it touches the fish. Immediately pour the seasoned soy sauce onto the fish.
Serve warm. The fish won’t hold sauce very well, so make sure you dip the fish meat into the sauce from the plate when eating. If the fish is not salty enough, you can add more seasoned soy sauce as you eat, according to your preference (see footnote 4).