For marinade, combine 2 tea spoons of the soy sauce, 2 teaspoons of the sherry, 2 teaspoons of the cornstarch and the salt in large bowl; mix well.
Add chicken; stir to coat well.
Let stand 30 minutes.
Combine remaining 3 teaspoons soy sauce, 3 teaspoons sherry, the vinegar, chicken broth, sugar and remaining 1 1/2 teaspoons cornstarch ir small bowl; mix well and set aside.
Heat 1 tablespoon of the oil in wok or large skillet over medium heat.
Add peanuts and cook until golden.
Remove and set aside.
Heat remaining 2 tablespoons oil in wok over medium heat.
Add chili peppers and stir-fry until peppers just begin to char, about 1 minute.
Increase heat to high.
Add chicken and stir-fry 2 minutes.
Add ginger; stir-fry until chicken is cooked through, about 1 minute more.
Add onions and peanuts to wok.
Stir cornstarch mixture and add to wok; cook and stir until sauce boils and thickens.