In bowl combine all batter ingredients and whisk until smooth, batter will be thin but that is what you are looking for.
Dip your chicken pieces one by one into the batter and then place into deep fryer.
Fry for about 7-8 minutes or until golden.
Turn out onto paper towel to drain, repeat will all chicken.
Sweet and Sour Sauce:
In small sauce pan combine your sugar, vinegar and water and heat on medium until sugar is desolved.
Meanwhile in small bowl stir together your ketchup and cornstarch.
Once sugar is desolved stir in the ketchup and cornstart mixtures.
Turn heat to medium high and bring to a boil.
Once mixture is boiling and it rises up in pan remove from heat and cool.
The batter for the chicken will be thin, do not worry about it, it sticks to the chicken hen frying and creates a nice and crispy coating.
Some people like to serve the sweet and sour sauce over the chicken itself, we don't recommend this as it makes the chicken soggy since it is breaded, but if that is how you are used to doing it by all means go for it!
Cut your chicken into larger pieces, 2" work best for actual restaurant size!
When adding chicken to deep fryer make sure your basket is down and add one at a time, this prevents it from sinking and sticking the the bottom of the grates.