Melt butter in a small saucepan and mix in flour. Stir for about a minute and add hot milk slowly and whisk. Allow the sauce to thicken slightly (boil for a few minutes) and strain into another saucepan. Add nutmeg, truffle oil, and both cheeses and mix over a low heat until the ingredients are well incorporated. Season to taste. Garnish with chives and fresh truffles.
SPRING VEGETABLES: Blanch and shock the first five vegetables. On a hot grill pan, grill artichoke, bok choy and asparagus. Arrange all of the vegetables around the fondue pot and serve.