Have a little potato water at the French castle (7)
I believe the answer is:
chateau
'french castle' is the definition.
(I've seen this before)
'have a little potato water at the' is the wordplay.
I cannot quite see how this works, but
'a' is within the answer.
'water' could be 'eau' (I have seen 'French water ' mean 'eau' so perhaps 'water' could also mean 'eau') and 'eau' is located in the answer.
'the' could be 't' (the is pronounced as a 't' sound in some dialects) and 't' is located in the answer.
The remaining letters 'ch' is a valid word which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for chateau that I've seen before include "Large French country house" , "French country home" , "Castle, especially in France" , "Manor-house in France" , "French stately home" .)