In a medium-sized mixing bowl, beat the egg white until it turns slightly foamy. Then whisk in remaining marinade ingredients. Transfer half of the mixture, about ¼ cup, into a small bowl and set aside. Cut turkey breast into 1-inch pieces and add to the remaining marinade in the medium bowl. Coat pieces well, cover, and refrigerate for 30 minutes
To make the orange sauce, combine soy sauce, cooking wine, rice vinegar, orange zest, orange juice, toasted sesame oil and corn starch in a small bowl. In a skillet, heat 2 teaspoons of oil, minced garlic, ginger and green onion over medium-low heat until fragrant, about 1 minute. Stir in the sauce mixture, marmalade, sugar and red chili flakes, and then heat until thickened, stirring frequently. Taste for seasoning and take off the heat. If the sauce thickens too much, reheat on low with a splash of water.
Combine dry coating ingredients in a medium bowl. Then, stir in reserved marinade and mix well to form small lumps.
Heat frying oil to 350°F. Meanwhile, give the marinated turkey meat a quick stir before coating with the dry flour-cornstarch mixture, pressing the coating onto each piece. When oil reaches temperature, fry turkey in batches until golden and crispy. Drain on paper towels. Coat cooked turkey meat in sauce and serve immediately with cooked white rice. Garnish with thinly sliced green onion.