Roasted Fillet Of Beef With Rosemary Au Jus

• 6 garlic (cloves)
• 3 reserved marinade
• 1 fillet (whole)
• 1 sauce
• 240 ml soy sauce
• 120 ml balsamic vinegar
• 90 ml beef stock
• 120 ml sherry
• 60 ml worcestershire sauce
• 30 gr corn starch mixed with