How to Make It
Preheat the oven to 375°. Spread the ciabatta cubes on 2 baking sheets and brush with oil. Bake for about 10 minutes, until crisp.
In a large saucepan, combine the Fontina, milk and cream and cook over moderate heat, stirring, until the cheese starts to melt, about 4 minutes. Whisk in the butter and egg yolks and cook over low heat, stirring, until very smooth, 3 minutes longer. Remove from the heat and season lightly with salt and pepper.
Transfer the Fontina fondue to a warmed serving bowl or fondue pot and sprinkle with truffle salt, if using. Serve right away with the toasted ciabatta and crudités.