Cut raw chicken into bite size pieces. Lightly roll raw chicken pieces in flour, this helps the batter to stick to the chicken and it also keeps the batter from sliding off the meat. Shake off excess flour, only a thin dusting is needed.
Mix the flour, cornstarch, baking powder and salt. Using a whisk, add enough very cold water until mixture feels like a pancake consistency, the thicker the batter, the puffier the chicken ball. Slightly thin batter is also good.
Fill a stainless steel pot only one third of the way with vegetable oil. (Over-filling a pot with oil may cause it to bubble and overflow and cause a fire.) Heat the vegetable oil to about 350°F. A deep fryer is recommended.
Using a fork, dip a piece of chicken into the batter to evenly coat. Carefully lower the battered piece of chicken into hot oil.
Deep frying at 350°F is the ideal temperature, but if you don’t have a thermometer, fry a small piece of battered chicken as a test first. Chicken ball should be a golden brown in about 7 minutes. If the chicken ball gets too dark too fast just lower the temperature. Remove the test piece and cut in half to check for doneness. Cooking times will vary, depending on how thick the piece of chicken is.To check for doneness insert a thermometer into the middle of a thick piece. The recommended doneness according to USDA is 165°F or 74°C.
