In a small mixing bowl, combine soy sauce, sesame oil, garlic, green onions, water, hoisin sauce, ginger and sugar. Mix well, add additional hoisin sauce to thicken mixture to your desired consistency if needed. Cover the sauce and refrigerate for 1 to 2 hours to allow flavors time to blend. Before serving, pour mixture into a small saucepan and heat, serve warm. NOTE: HOISIN SAUCE IS ALSO CALLED PEKING SAUCE, IS A THICK, REDDISH-BROWN SAUCE THAT IS SWEET AND SPICY, AND WIDELY USED IN CHINESE COOKING. CAN BE FOUND IN ASIAN OR ETHINIC SECTIONS OF STORE.