Type of bread mine, thank you (5)
I believe the answer is:
pitta
'type of bread' is the definition.
(I've seen this before)
'mine thank you' is the wordplay.
'mine' becomes 'pit' (down the pit).
'thank you' becomes 'ta' (informal way of saying thank you).
'pit'+'ta'='PITTA'
(Other definitions for pitta that I've seen before include "Greek unleavened bread" , "I might have a kebab in" , "(E.g. Greek) bread" , "Flat sort of bread" , "Partially-leavened bread of the Near East" .)