Soak mushrooms in two cups of lukewarm water for half an hour. In a small bowl, combine milk & bread, and mash until creamy. In a large bowl, break up the beef with a fork. Add milk and bread mix, along with the onion, salt, pepper, prosciutto, cheese and garlic. Mix thoroughly by hand. Mix in the lightly beaten egg yolk. Shape meat into a firm, round ball, then roll this into a salami- like loaf about two and a half inches thick. Roll in the bread crumbs until evenly coated.
Drain mushrooms (reserving the soaking water.) Chop roughly and set aside. Whisk the tomato paste into the soaking water. Set aside. Heat butter and vegetable oil in a heavy casserole pan just big enough for the meat. Brown meat on all sides in the pan over medium heat. Add wine and increase meat to medium high. Boil wine briskly until reduced by half, turning meat carefully once or twice. Turn heat to medium low and add chopped mushrooms and the tomato paste mushroom water. Cover and simmer for 30 minutes, turning the meat once or twice.
Remove meat to a cutting board. Allow it to cool and settle. Cut into slanted slices about 3/8 of an inch thick, and serve with sauce. Feeds four.
Appeared in print on 3/3/10