Marinade the chicken pieces with all marinade ingredients and set aside for atleast 30 minutes.
In a deep skillet or wok, heat oil until hot. Add chicken to oil and fry chicken for about 15 minutes. Remove chicken and set aside.
Heat more oil in skillet or wok until hot. Add onion, green onion, ginger, garlic, and red chillies and saute for about 10 minutes.
Add fried chicken pieces, soy sauce, red chilli powder, vinegar, sugar, salt, and chicken stock. Mix and bring to a boil. Add liquid corn flour and mix, cook for about 5 minutes by mixing until the curry thickens a bit.
Add chili oil and mix, simmer on very low heat for about 5 minutes and remove from heat.