Kalbsbrust Mit Krauterfullung

• 4 mushroom (pieces)
• 3 egg
• 1 onion
• 1,000 gr leg of veal
• 800 gr boned veal breast
• 475 ml beef broth (hot)
• 230 gr beef (ground)
• 200 ml sour cream
• 55 gr bread crumbs
• 16 gr cornstarch