Rinse chicken and pat dry with paper towels. Cut chicken crosswise into 1/4 inch thick slices. Combine chicken and cornstarch in a large bowl. Add egg white; stir to combine. Set aside.Mince ginger and garlicCombine sherry, soy sauce, sesame oil, sugar, red pepper, and salt in a cup. Set asideHeat the wok over high heat about 1 minute or until hot. Drizzle vegetable oil into the wok and heat 30 seconds. Add chicken mixture and stir fry until chicken is no longer pink in the center. Remove chicken to a large bowl.Reduce heat to medium.Add ginger and garlic to the wok; stir fry 30 seconds. Add green pepper and onions; stir fry 1 minute. Return chicken to the wok. Add peanuts and sherry mixture; stir fry until well mixed and heated through.Transfer chicken mixture to a serving dish.Serve with hot cooked rice, if desired.