Thoroughly rinse and dry the fish. Heat a well-seasoned wok over a high flame until very hot, add oil and swirl around the wok to cover sides. Turn heat down to medium, and holding the fish by the tail, carefully slide it into the pan head first. Add the second fish alongside it. Let the fish cook undisturbed. After about 3 minutes you should be able to move the fish easily by shaking the pan and be able to gently left the fish with a spatula and check the color. Continue cooking until the skin is nicely golden brown.
While fish cooks, add soy sauce, vinegar, both kinds of chili bean paste, sugar and Shaoxing wine to a measuring cup. Add enough water to make ¾ cup sauce.
To flip the fish over, gently slide the spatula under the center of one fish and flip it over toward the outside of the wok. Do the same for the second fish, flipping it over toward the edge of the wok on the other side. If the fish is too heavy or unwieldy, you can use two spatulas to do this. Cook on second side for about 4 minutes, or until crispy gold. Move the fish to the sides slightly with the spatula to leave a well of oil in the middle of the wok. Add the garlic and ginger and cook briefly.
Poor the sauce directly over the fish, making sure to wet all of it, and carefully distribute the sauce around both fish. Sprinkle the green onions over and around the fish, cover the wok with a lid, and gently braise the fish, checking every couple minutes to check doneness. Check with a fork to make sure the fish is cooked through and easily flakes, then remove them to a serving plate. Pour sauce over fish and garnish with more scallion greens if desired.
Notes
Substitutions: use a neutral frying oil in place of the rapeseed oil; use only one kind of Pixian doubanjiang instead of the combo; substitute golden or dry sherry for the Shaoxing wine