How to do it
Cut fontina and emmenthal cheese in little cubes. Put the milk in a pot and add fontina and emmenthal, only with flame out . Take a pot with some water and put a smaller pot with the butter in water bath. Light the flame and when the butter is perfectly melted you can add fontina and emmenthal cheeses without the milk in which you put them before. Cook 10 minutes and stir everything continuously to melt cheeses. On the side beat the egg yolks with a whip .at this step add the cheese and white truffle cream, the boiled, peeled and mushed potatoe and keep on turning well. Take the little pot, dry it externally.now you can take it to the table covering it with white truffle slices, toasted bread to stuff with white truffle fondue.