Having finished pack I smoked joint (8)
I believe the answer is:
pastrami
'smoked joint' is the definition.
(I've seen this before)
'having finished pack i' is the wordplay.
I cannot quite see how this works, but
'finished' could be 'past' and 'past' is found within the answer.
'pack' could be 'ram' (synonyms) and 'ram' is located in the answer.
'i' is found in the answer.
This accounts for all the letters.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for pastrami that I've seen before include "Highly seasoned cut of smoked beef" , "Spicy smoked beef" , "Smoked, highly-seasoned cut of beef" , "smoked joint" , "Spiced smoked beef" .)