If you are not using a fryer, heat up 8 cups of vegetable oil in a heavy pot until the temperature reaches 360 degrees.
Make the batter by combining flour, cornstarch, sugar, salt, baking powder, baking soda, onion salt, paprika, ground black pepper. Stir to combine all dry ingredients. Add club soda to dry ingredients. The batter will foam, continue to stir.
Drop pieces of chicken into the batter. Coat chicken with batter, drop into the hot oil. Fry chicken for 2 to 3 minutes on each side or until the batter is golden and the chicken pieces begin to float to the top of the oil. Drain chicken on a wire rack.