Mix all the sauce ingredients together in a small bowl and set aside
Mix the chicken with the vegetable oil, egg and salt
Mix in the cornstarch and evenly coat the chicken
Heat a heavy-bottomed skillet - a cast iron if you have one - until hot, and then carefully add in the oil
Add chicken into a single layer in the skillet and cook without moving for 2 to 3 minutes, or until the bottom turns golden
Turn each piece over and cook the other side for 2 to 3 minutes or until cooked through and then transfer to baking pan in a single layer and set aside
Allow the pan to cool a little and then add in the green onion, garlic, and ginger and cook for 30 seconds
Add in the peppers and cook for 1 minute
Stir the sauce mixture to make sure the cornstarch is mixed in and pour into the pan
Stir until it thickens and then add in the pineapple and warm through - about 1 minute
Add in the chicken and gently stir to coat in the sauce
Serve over steamed rice and enjoy