Preheat oven to 180 degrees C. or 320 degrees F. In a large bowl, add egg, soy sauce, 1 tablespoon of Rice Wine Vinegar. Whisk together with a fork, add chicken strips and coat with marinade.
In a large bowl, add ½ cup of cornflour (or cornstarch) and 1 teaspoon Chinese five spice powder. Mix to combine.
Remove chicken strips from marinade one at a time, shake off excess and dip in cornflour/cornstarch, until coated. Place strip on a large oiled baking tray. Repeat until all chicken strips are done. Discard the marinade.
Spray chicken strips again all over with a quick 3 second spray, making sure there are no big white spots of cornflour/cornstarch visible.
Bake for 15 minutes. Make sauce whilst chicken is baking.
When chicken is cooked, use a spatula to lift the pieces off, making sure to scrape up all the crunchy bits – you want to keep those. Put chicken into a large bowl ready for the sauce.