In a mixing bowl, combine the Gruyère cheese and Emmental cheese. Add the cornstarch and toss the shredded cheese until it’s completely coated with the cornstarch. Set aside.
Rub the inside of an electric fondue pot with the garlic clove halves.
Then, add the wine to the fondue pot. Turn the heat to medium and cook for 2-3 minutes, until the wine simmers.
Reduce the heat of the fondue pot to low after the wine comes to a simmer. Stir in the lemon juice, ground mustard, nutmeg and black pepper.
Gradually add the shredded cheese mixture to the pot handfuls at a time and stir with a rubber spatula. Continue until the cheese is all melted and smooth. This will take about 4-5 minutes.
Add the Kirsch or Cognac to the cheese fondue and stir to combine.
Leave the heat on low to serve the cheese fondue, stirring occasionally so that a film does not form on top of the cheese.
Serve with your favorite gluten-free dippers, like gluten-free bread, blanched broccoli, and tart green apples. Enjoy!