To make sauce, mix cornstarch and water together. Add garlic, ginger, sugar, soy sauce and vinegar . Then add chicken broth and M.S.G. and stir until sugar dissolves. Refrigerate until needed.
In separate bowl, mix chicken, soy sauce and 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° until crispy. Drain on a paper 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.
Serves 6 – 8.