To make sauce, mix 1/2 cup cornstarch and water together. Add garlic, ginger, sugar, 1/2 cup soy sauce, vinegar and wine. Then add chicken broth and M.S.G. and stir until sugar disolves. Refrigerate until needed.
In separate bowl, mix chicken, 1/4 cup soy sauce and white pepper. Stir in egg. Add cornstarch until chicken is coated evenly. Add oil to help separate chicken pieces. Divide chicken into small quantities and deep-fry at 350 degrees until crispy. Drain on apaper towel.
Place a small amount of oil in wok and heat until wok is hot. Add scallions and peppers and stir-fry briefly. Stir sauce; add to wok. Place chicken in sauce and cook until sauce thickens. Add either cornstarch or water as needed. Serve with rice.