Rub the garlic clove (if using) around the inside of a fondue pot or nonaluminum saucepan, then discard. Add the wine and heat to boiling. Reduce flame (or stovetop) to low and add the Alfredo sauce, Swiss cheese, and nutmeg. Stir constantly until the cheese is melted and very hot. Add the kirsch or brandy (if using).
Serve with cubes of bread, sliced pears, and sliced apples.
The perfect cheese fondue is unctuously rich, nutty yet sweet, and as fun to eat as s'mores. Traditional recipes call for two or three kinds of cheese, such as Gruyère and Emmentaler, slowly and carefully melted together and thickened with cornstarch.