1. Rub the cut side of the garlic clove inside the fondue pot and discard the garlic. Add the wine and lemon juice to the pot and bring it to a boil on the stove over medium heat. Reduce the heat to low. Toss the Gruyére and Emmental cheeses in a bowl with the cornstarch. One handful at a time, stir the cheeses into the wine, mixing until the cheeses melt before adding more.

2. Cook, stirring constantly, until the fondue just comes to a simmer. Stir in the kirsch, and season with pepper.

3. If the fondue is too thin, add more cheese or stir in cornstarch dissolved in wine. If too thick, stir in a little warmed white wine.

4. To serve, transfer the pot to its stand on the table. Spear the bread cubes onto fondue forks and dunk into the cheese.