Bishop can mangle strange dessert (10)
I believe the answer is:
blancmange
'dessert' is the definition.
(blancmange is a kind of dessert)
'bishop can mangle strange' is the wordplay.
'bishop' becomes 'B' (chess abbreviation).
'strange' indicates an anagram.
'can'+'mangle'='canmangle'
'canmangle' is an anagram of 'lancmange'.
'b'+'lancmange'='BLANCMANGE'
(Other definitions for blancmange that I've seen before include "Wobbly dessert" , "Jelly-like dessert" , "Table cream" , "Pudding made with milk - ABC man, Glen (anag)" , "Jelly-like pudding made with milk" .)