Place the chicken cubes in a bowl, add all the ingredients for the marinade, mix well and set aside for ten minutes.
Meanwhile, mix together all the ingredients for the sauce.
In a wok heat enough cooking oil to reach a depth of one-half inch.
Spread the marinated chicken in the hot oil and cook over medium heat, turning the over a few times, until cooked through, about seven minutes.
Scoop out the chicken and set aside.
Pour off the oil leaving only two tablespoonfuls.
Stir fry the white/light green portion of the scallions with the bell peppers for about half a minute.
Add the peanuts and cook, stirring often, until heated through.
Pour in the sauce and cook for about a minute until slightly reduced and thickened.
Throw the chicken back into the wok and continue stir frying until every piece of chicken is coated with sauce.
Tip the contents of the wok into a shallow bowl and sprinkle your kung pao chicken with the dark green portion of the scallions before serving.