1. Place the egg into a bowl, add corn flour and a pinch of salt. Whisk well to combine.
2. Dry chicken breast with kitchen towel. Coat chicken with egg mixture.
3. Heat the wok until smoking and add oil. Fry the chicken for 4-5 minutes, or until golden brown and crisp, then remove from wok and drain on absorbent kitchen paper.
4. Remove all oil from wok, left one tablespoon. Reheat the oil over high heat, add the onion and stir-fry for a few seconds. Add the yellow and red pepper slices and stir-fry for 1 minute, or until softened.
5. Add the chicken pieces and stir-fry for 1-2 minutes, then add light soy sauce. Simmer for another minute, or until the chicken is cooked through.
6. Stir in the spring onions and cashew nuts, add sea salt and ground white pepper to taste and transfer to a serving dish. Serve immediately with steamed rice.