Combine chicken and 2 tbsp soy sauce, refrigerate 30 minutes.
Combine remaining 2 tbsp soy sauce, lemon juice from concentrate, sugar, cornstarch, crushed pepper and ¼ cup water.
In wok or large skillet, stir-fry chicken and garlic in hot oil 3 minutes. Add cornstarch mixture. Cook and stir until slightly thickened.
Add peanuts and serve.
Refrigerate leftovers (there probably won't be any!).