1. Place the milk in a saucepan and warm it up gently. Turn off just before it boils.
2. Cut the ham into small pieces.
3. Melt the butter in a sauce pan and add ham.
4. Let it sauté for one minute and then add the wheat and corn flour. Stir well while it thickens and continue to stir until it begins to smell slightly nutty. Be careful that it does not become too dark.
5. Add the hot milk a little at a time while stirring.
6. Remove the dough from the heat and add chunks of cheese.
7. Now whip the dough thoroughly with either an electric whisk or a mixer until the consistency is soft and fluffy and the cheese has melted.
8. Let the dough cool in the refrigerator for at least four hours.
9. Add dried porcini mushrooms in a blender and blend until the mushrooms has a consistency like breadcrumbs.
10. Put some flour in a soup plate. Beat the eggs together in a second bowl. Mix breadcrumbs and blended Pucini mushrooms in a third.
11. 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.
12. Heat the frying oil in a saucepan. When the oil sizzles, it is warm enough. Fry the croquettas until they are golden and crisp. Only fry a couple at a time to avoid that they stick together and to keep the oil from cooling down.
13. Remove the fried balls and place them on fat absorbent paper. Let them cool down a bit - they taste the best when they are not burning hot.
14. Serve the croquettas with a good, thick balsamic or sherry vinegar and thin slices of cured ham.