Sent back kind of pudding the French consumed: it's very rich and creamy (6)
I believe the answer is:
eclair
'it's very rich and creamy' is the definition.
'sent back kind of pudding the french consumed' is the wordplay.
'sent back' is a reversal indicator.
'kind of pudding' becomes 'rice' (I've seen this in another clue).
'the french' becomes 'la' ('the' in French).
'consumed' is an insertion indicator.
'rice' backwards is 'ecir'.
'ecir' placed around 'la' is 'ECLAIR'.
(Other definitions for eclair that I've seen before include "Lacier type of cake" , "Long (but not long-lasting) cake" , "A long choux cake" , "Finger-shaped cream-filled cake of choux pastry" , "teatime treat?" .)