Place a heavy, preferably cast iron pan on high heat and add ¼ to ½ a cup oil (I used ½ a cup) - I know this is still not a small amount, but I promise you, most of it will ooze out during the second stage of cooking. Set a large metal sieve over a bowl in such a manner that the sieve is resting well above the bottom of the bowl.
In a large bowl, add ½ a cup cornflour, then add 6 to 8 pieces of the marinated chicken. Toss each piece around in the cornstarch, pressing down a bit so that the cornflour adheres to the chicken in lumps.
When the oil is hot (about 180 - 190 ° C), take a piece of chicken, shake off the excess flour and add to the oil. It should sizzle immediately. If the oil is ready, add in a few more pieces of the chicken, remembering to shake off excess flour. Do not to crowd the pan - the chicken pieces also should have enough room around them so that they don't stick to each other.
In about 2 minutes, check the underside of the chicken pieces. When you see the batter setting and the colour changing to a pale yellow, flip the chicken pieces over. Fry for another minute or so until the chicken looks evenly coloured all over. Remember, we're NOT cooking the chicken completely at this stage. Remove the pieces to the sieve. Before adding the next batch, fish out as much debris from the oil as possible. Repeat with all the chicken pieces and set aside. Remember to maintain the temperature with each batch, adjusting it to high or low as required.