1. If you don't have homemade chicken stock you may dissolve 1-1/2 stock (bouillon cubes) in 2 cups of warm water and use that instead. However do note that stock cubes are high in salt and also have preservatives, so use your discretion and adjust the salt used for the marinade 2. If you find black mushrooms or any other kind of mushrooms used in oriental cuisine you may use those as well.