Defrost teriyaki chicken morsels in the microwave oven for 2 minutes. Set aside.
Note: You can also use fresh chicken thigh meat (cut into bite-size pieces) instead. If so, you may want to adjust the amount of seasoning by adding slightly more soy sauce and sugar.
In a bowl, mix ingredients for sauce and set aside.
In a small frypan (20cm or smaller), add some oil and fry 1/3 of the onions over medium heat till slightly browned. Add 1/3 of the sauce mixture and 1/3 of the chicken. Fry for a short while, then cover pan with lid and cook for 3-4 minutes. If using raw chicken, cook for a little longer (4-6 minutes).
Note: Cook 1 serving at a time.
Add 1/3 of the egg mixture into pan and cover pan with lid. Reduce to low heat and cook for about 30 seconds to 1 minute (for slightly runny egg), or till egg is cooked to your preferred doneness.
Slide egg and chicken onto a bowl of piping hot rice. Garnish with spring onions and seaweed if desired. Serve.