Cut chicken into small pieces (each should be a little larger than the peanuts). Mix chicken with salt, 1 teaspoon soy sauce and 1 tablespoon cornstarch.
Split scallion lengthwise and cut into 1 inch sections. Cut garlic into slivers.
In a small bowl, mix together the remaining soy sauce and cornstarch, MSG, sugar, vinegar, sherry, scallion, garlic, ginger and sesame oil. Set aside.
Heat oil in frying pan. Add peanuts and stir until golden. Add hot pepper flakes, then chicken. Cook for 1 minute. Add the soy sauce mixture to the chicken and cook just until sauce thickens and coats the chicken.