Cut the beef, pork and chicken into silver dollar sized medallions about 1/4 " thick. Pound each lightly to flatten. Insert a bamboo skewer into each medallion, keeping the medallions as flat as possible. Combine the soy sauce, ginger, garlic, pepper, water and sugar in a small bowl. Arrange the satays in the marinade with their skewers resting on the edge of the bowl.
Cover with plastic wrap. Refrigerate 3 hours or longer. Wash and trim the green onions. Make several lengthwise cuts through the green ends. Place, green side down, in a small bowl of ice water. Cover. Refrigerate. Preheat the broiler. Arrange the satays on the broiler pan with the skewers all on one side. Cover the skewers with foil. Broil 3" from the heat for 3 minutes. Turn. Broil until done to taste (roughly 2 minutes longer). Remove chicken and beef satays. Cook