Clue: Thick soup — food to the German (7)
Answer: CHOWDER
Explanation: Definition: Thick soup
CHOW + DER – contrary to my suspicions, I found that "chow" and "chowder" are unrelated: "chow" is from Chinese pidgin English "chow chow", from Chinese "cha"="mixed"; "chowder" from old French "chaudière", meaning a pot (and related to "cauldron")