Rub the inside of the fondue pot or a medium pot with the cut side of the garlic halves.
Place the fondue pot on the stove over medium low heat and add the butter.
Once melted, add the the thinly sliced shallots.
Cook, stirring occasionally while adjusting the heat between medium low and low, until golden and caramelized, about 20-30 minutes. Stir in the salt.
Add the white wine to the pot and bring to a simmer.
In a large bowl, toss the freshly grated Gruyère with the cornstarch.
Once the white wine is simmering, reduce heat to low.
Stir in handfuls of the coated cheese until melted and smooth.
Season as desired with black pepper and nutmeg.
Transfer the fondue pot to the table-side burner (set to medium-low/low) and stir in the Kirschwasser.
Serve the fondue immediately with cubed bread, boiled potatoes, along with cornichons and pickled pearl onions on the side.