Heat 1/2 cup cream in a heavy non-reactive saucepot over moderate heat until cream comes to a low boil. Remove the pan from the heat and add chocolate. Let the chocolate stand in hot cream 3 to 5 minutes to soften, then whisk chocolate together with the cream. Stir in liqueur and/or chopped nuts and transfer the fondue to a fondue pot or set the mixing bowl on a rack above a small lit candle. If fondue becomes too thick, stir in reserved cream, 1 tablespoon at a time, to desired consistency. Arrange your favorite dippables in piles on a platter along side chocolate fondue with fondue forks, bamboo skewers or seafood forks, as utensils, for dipping.