Preheat a wok over moderate heat until hot.
While the wok heats up, toss the fish in a shallow bowl with the cornstarch, ½ teaspoon salt, and ¼ teaspoon white pepper.
When the wok is ready, add 2 Tablespoons canola oil and swirl to coat. Add the fish and stir-fry until golden brown, turning as needed, about 3 minutes. Remove to a plate.
Return the wok to moderate heat. Add the remaining 1 Tablespoon canola oil followed by the ginger, garlic, chili peppers, carrot, bok choy, and a pinch of salt and white pepper; stir-fry until the carrot and bok choy are just tender to the bite, 3-4 minutes.
Return the fish to the wok and add the soy sauce and sesame oil. Stir-fry for about one minute.
To serve, divide the stir-fry between bowls of rice and garnish with seaweed strips.
