1. Bring the wine to a simmer in a small saucepan.
2. Meanwhile, melt the butter in a medium saucepan over medium low heat. Whisk
in the flour, and cook for about 5 minutes, stirring constantly to avoid
sticking and burning.
3. Once the flour is cooked, stir the wine into the flour mixture slowly. Use
a whisk to smooth the mixture. Slowly add cubes of Gruyere, Cheddar, and Emmentaler
cheese; stir until cheese is melted. Transfer cheese mixture to fondue pot.
Keep warm over low flame.
