Rub the inside of a saucepan with the cut side of the garlic and then discard the garlic.
Add the wine and cornstarch to the prepared pan and bring it to a boil.
Reduce the heat so the wine is just simmering and add the cheese, nutmeg, black pepper, and paprika, stirring constantly until the fondue is melted and smooth.
Keeping the heat low to medium, continue cooking, never boiling, the fondue for 15 minutes until it is thickened.
Add the Kirsch (if using) and stir constantly for 1 minute.
Transfer the fondue to a fondue pot set over a flame and serve it with cubed bread.