Start to heat the cooking oil for deep frying. The temperature should ideally be between 180-190 degree Celsius/ 356-374 degree Fahrenheit.
While the oil is heating, put the chicken into a large mixing bowl and add the egg, flour, corn flour, salt to taste and pepper to it. Mix well until the other ingredients form a thick paste that coats the chicken well. If the paste is not thick enough, sprinkle a little more corn flour and mix well.
Once the oil is hot, gently add a few battered chicken pieces at a time and fry till crisp and golden in color. Drain well and remove from the oil. Keep aside on paper towels for later use.
In another pan or wok, heated on high, add the 3 tablespoons vegetable/canola/sunflower cooking oil. When the oil is smoky hot, add the spring onions (reserve a little to garnish the dish later). Saute for a minute.
Now add the Indo-Chinese Szechuan Sauce and chicken stock. Mix well. Cook for 2 minutes.
Omit this step if you want the dish to be a dry one or would like to serve it as an appetizer: Mix 1 tablespoon of corn flour with 1/2 cup of cold water and stir to mix well. Make sure there are no lumps in this mixture. Pour into the above gravy and stir well. The gravy will start to thicken. Once this happens, turn off the heat.
Now add the previously fried chicken pieces to this gravy. Stir well to coat all the chicken with the gravy. Spoon into a serving dish, garnish with reserved, chopped spring onions and serve.