Possible Clues:

• Thin soup
• Clear soup made from meat stock
• Argument against last of cream going in a portion of soup
• Many more than a hundred in the soup on this awful battle
• Many on river having soup
• Prisoner facing battle to get a starter course
• Do battle as a clear starter?
• Clear French meat soup
• Disadvantage found by millions in an unspecified stock product
• And so up, as a matter of course