Rub the inside of a small, 2-quart Dutch oven with the cut garlic, then add the wine, brandy, and lemon juice. Place over medium heat until the liquid reaches 135°F, or it just begins to steam.
While the liquid is heating, thoroughly toss the cheeses together in a large bowl with the cornstarch and white pepper.
When the liquid hits 135°F,start stirring in the cheese, one handful at a time, using a spatula. Wait until the last addition is almost melted before adding the next.
When all the cheese is in the pot, increase the heat slightly and switch from the spatula to a whisk. Whisk constantly until the mixture lightens in color and is smooth. Add the horseradish and continue whisking until the fondue pours off the whisk in a ribbon and coils on the surface of the cheese like a rope before dissolving, about 5 minutes.
When the cheese is melted, remove from the heat, place the lid on the pot, and take to the table. Serve alongside bread chunks for dipping. I like to mix up torn and toasted pieces of sourdough, pumpernickel, and challah. Some folks will tell you to serve vegetables...whatever.