In medium saucepan, place the fontina cheese with flour, and mix. Add the milk and mix well with a wooden spoon. Let rest for 1 to 2 hours.
In a medium skillet, melt butter on medium heat. Cook the bread cubes, until slightly toasted. Hold aside.
Place saucepan on stove top on medium-low heat, cook, stirring with the wooden spoon until cheese is well melted and combined with the other ingredients. Remove from stove top. In a small bowl, whisk the egg yolks, whisk in some of the cheese mixture to temper it. Then add the yolk mixture back into the saucepan. Mix well to incorporate all ingredients. Place back onto stovetop on medium heat and continue stirring.
Serve the cheese mixture in individual molds. Garnish with shavings of truffles and place the cubed bread on the side.
Professional Recipe: This recipe was provided by a chef, restaurant or culinary professional and makes a large quantity. The Food Network Kitchens chefs have not tested this recipe in the proportions indicated and therefore cannot make any representation as to the results.