French drink tea with delight, mostly (7)
I believe the answer is:
chablis
'french drink' is the definition.
'Chablis' can be an answer for 'drink' (Chablis is an example). I'm not sure about the 'french' bit.
'tea with delight mostly' is the wordplay.
'tea with' becomes 'cha' (I can't justify this - if you can you should give a lot more credence to this answer).
'delight' becomes 'bliss' (I've seen this before).
'mostly' means to remove the last letter (most but not all of the word).
'bliss' with its final letter removed is 'blis'.
'cha'+'blis'='CHABLIS'
Can you help me to learn more?
(Other definitions for chablis that I've seen before include "French town noted for white Burgundy wines" , "Burgundy town and white wine" , "Classic white wine from Burgundy" , "Drink" , "Dry white Burgundy" .)