Cut the chicken thighs into small pieces that are approximately 1x1 inches.
In a deep bowl, mix flour, cornstarch, salt, pepper with water, oil and egg. Use the mixer so the batter doesn’t have any lumps.
Put the chicken into the batter, stir well and leave it in the fridge for at least 30 minutes. You can also leave it overnight and then prepare it the next day.
Fry the chicken pieces in batches, in deep and heated oil until golden, for about 3 minutes. Put the fried chicken on a paper towel and repeat for all the chicken.
Stir fry the chilli flakes, chopped ginger and garlic. Add white and brown sugar and stir all the time. When the sugar is melted, add fresh orange juice, soya sos and vinegar. In a cup, whisk together cornstarch with water until there are no lumps and then add it to the sauce.
When the sauce is thick, add fried chicken and stir for one more minute.