Break the hard bread into pieces, put it in a bowl, add the milk and leave to soak for about ten minutes.
Put both types of meat in a bowl and add the egg.
Also add the grated cheese, then season with salt and black pepper.
Chop a bunch of parsley and add it to the mixture.
Squeeze the soaked bread, add it to the meat mixture and knead with your hands, then transfer to the refrigerator for 15 minutes.
If after the fridge the dough is still too soft, you can add 1-2 tablespoons of breadcrumbs.
Grease your hands with a drizzle of oil, form the balls and roll them in the flour, then put them back in the fridge for 10 minutes.
Meanwhile, clean the mushrooms.
Cut off the base full of earth, clean them with a damp cloth and cut them into thin slices.
Crush a clove of garlic with the side of the blade of a knife without peeling it.
Fry the garlic clove in a pan with a drizzle of oil, then add the meatballs and brown them on the outside.
Add the sliced mushrooms while they are cooking and add a pinch of salt.
Cook for five minutes on a moderate flame.
Deglaze with the white wine, lower the heat and cook for about ten minutes.
When the sauce thickens, turn off the heat and serve with a handful of chopped parsley.