Best Yet Onion Soup

• 10 3/4 size
• 5 sweet onions (yellow)
• 1 cheese
• 700 ml beef broth
• 110 gr mozzarella (grated)
• 14 gr margarine
• 16 ml olive oil
• 10 gr parmesan cheese
• 8 gr flour
• 1 gr coarsely pepper (ground)