Some potato? A lot ordered with a snack in the tube (9)
I believe the answer is:
chipolata
'snack in the tube' is the definition.
(tube-shaped food)
'some potato? a lot ordered with a' is the wordplay.
'some potato?' becomes 'chip' (chips are made from potatoes).
'ordered with' indicates an anagram.
'a'+'lot'='alot'
'alot' mixed up with 'a' can make 'olata'.
'chip'+'olata'='CHIPOLATA'
(Other definitions for chipolata that I've seen before include "Type of sausage" , "Party snack" , "Small thin sausage" , "banger" .)