New store stocks British dessert (6)
I believe the answer is:
sorbet
'dessert' is the definition.
(sorbet is a kind of dessert)
'new store stocks british' is the wordplay.
'new' indicates anagramming the letters.
'stocks' is an insertion indicator (stocks can mean carries or contains).
'british' becomes 'b' (abbreviation e.g. in 'BBC').
'store' is an anagram of 'soret'.
'soret' placed around 'b' is 'SORBET'.
(Other definitions for sorbet that I've seen before include "Fruit water-ice" , "Water ice dessert" , "Granita-like dessert" , "Sherbet, water-ice" , "Frozen dessert" .)