1. Place the milk in a saucepan and warm it gently over a low heat. Take off the heat just before it boils.
2. Melt the butter in a medium saucepan and add the prosciutto.
3. Let it sauté for one minute and then add the plain flour and corn flour. Stir well until it thickens and continue to stir until it begins to smell slightly nutty. Be careful that it does not become too dark.
4. Add the hot milk a little at a time while stirring.
5. Remove the dough from the heat and then add slices of Castello® Double Cream Truffle.
6. Whip the dough thoroughly with either an electric whisk or a mixer until the consistency is soft and fluffy and the cheese has melted. Let the dough cool in the refrigerator for at least four hours.
7. Place the dried porcini mushrooms in a blender or food processor and blend until the mushrooms have a consistency like breadcrumbs.
8. Place some flour onto a large plate. Beat the eggs together in a second bowl. Mix breadcrumbs and blended porcini mushrooms in a third.
9. Form small balls of dough (a few centimeters in diameter). Roll them in flour, then in the beaten egg and finally in breadcrumbs and Pucini mushrooms. Be sure the breading covers the ball completely.
10. Heat the oil in a large saucepan. When the oil sizzles after dropping a piece of breadcrumbs in, it is hot enough. Fry the croquettes until they are golden and crisp. Only fry a three of four at a time to avoid the oil losing temperate and croquettes sticking together.
11. Remove the croquettes and place them on paper towel. Let them cool down slightly, they taste best when they are not burning hot! Serve the croquettes with a good, thick balsamic and extra thin slices of prosciutto.