Combine Gruyere cheese, Emmenthal cheese, and cornstarch in a bowl.

Rub the inside of a saucepan with garlic halves, leaving garlic in the pan.

Add white wine and lemon juice to the saucepan.

Bring the liquid to a simmer.

Gradually add the cheese mixture to the wine, stirring constantly until melted and smooth.

Stir in kirsch, nutmeg, minced chipotle chilies, and pepper.

Transfer the fondue to a fondue pot and keep warm over a low flame.

If desired, stir in fried shallots, scallions, or bacon.

Serve the fondue with assorted cooked vegetables, bread sticks, and cubes of bread for dipping.

To make fried shallots, cook sliced shallots in vegetable oil over medium-high heat until golden brown.

Drain shallots on paper towels and season with salt.