Roast Meat Loaf or Hedgehog

Name: Roast Meat Loaf or Hedgehog
Ingredients: 8 ounces mushrooms, sliced; Butter; Salt; Freshly ground black pepper; Grated nutmeg; 8 ounces chicken livers; 1 pound each ground beef, ground pork, ground veal; 1 pound sausage meat; 1 large onion, grated; 3 fat cloves garlic, crushed to a paste; 10 juniper berries, crushed; 1 teaspoon ground allspice; Fresh thyme sprigs; 1 to 2 eggs; 8 ounces unsmoked bacon; Bay leaves; Branches of fresh rosemary; Tomato sauce, for serving