In a large mixing bowl, whisk together all the batter ingredients until combined. The batter should be thin and runny but still able to coat the fish.
Slice the fish fillets into 1.5-inch-long and 1-inch-wide pieces. Pat dry with paper towels. Add the fish to the batter and gently mix until evenly coated, being careful not to break the pieces.
Heat 1.5 inches of vegetable oil in a large, heavy-bottomed pan over medium-high heat to 350°F (180°C). Use a cooking thermometer to check the temperature. If you don't have one, insert a wooden chopstick into the oil and look for steady bubbles around it.
Carefully lower one-third of the battered fish into the hot oil, separating the pieces so they don't stick together. Fry for 5-7 minutes, turning occasionally, until golden brown and crispy and the fish reaches an internal temperature of 145°F (63°C). Transfer to a wire rack to drain excess oil. Repeat with the remaining fish in two batches, allowing the oil to return to 350°F (180°C) between batches.
In a small pot, whisk together the canned creamed corn, chicken bouillon powder, Shaoxing wine, minced garlic, cornstarch, cold water, and peas. Bring to a boil over medium heat, stirring frequently until thickened. Reduce to a gentle simmer and drizzle in the beaten egg in a thin stream, stirring gently to create delicate egg ribbons. Remove from the heat.
Serve the crispy battered fish immediately with the warm cream corn sauce on the side, or pour the sauce over the fish just before serving.