Plain-spoken French knight tucks into pastry (2,5)
I believe the answer is:
en clair
'plain-spoken french knight tucks into pastry' is the definition.
I can't tell whether this defines the answer.
'knight tucks into pastry' is the wordplay.
'knight' becomes 'N' (chess abbreviation).
'tucks into' means one lot of letters goes inside another.
'pastry' becomes 'eclair' (eclair is a kind of pastry).
'n' inserted within 'eclair' is 'EN CLAIR'.
Can you help me to learn more?
(Other definitions for en clair that I've seen before include "Not in code or cypher" , "in the Open" , "in ordinary language" , "N ot in code/cipher" , "in plain language" .)