Place the Enjuku Koji Miso Liquid, peanut butter, sugar and water into a bowl, mix the ingredients well; set aside.
Heat 1 tbsp. oil in a wok and stir-fry the green beans for 3 minutes. Add the chicken to the wok, and sauté until chicken is cooked through; add the miso peanut sauce and stir-fry for another 1 to 2 minutes until the sauce has thickened.