Rub the inside of a medium saucepan or fondue pot with the cut sides of the garlic. Discard or leave the clove in for subtle flavor.
Add the white wine and lemon juice. Warm over medium heat until gently steaming (not boiling).
In a separate bowl, toss all shredded cheeses with cornstarch. This prevents clumping and keeps the fondue smooth.
Add cheese a handful at a time, stirring constantly in a figure-eight motion until fully melted before adding more.
Stir in Dijon mustard, Worcestershire sauce, nutmeg, and black pepper. Taste and adjust salt if needed.
Reduce heat to low and serve immediately
