Dessert order includes unfilled bombe (6)
I believe the answer is:
sorbet
'dessert' is the definition.
(sorbet is a kind of dessert)
'order includes unfilled bombe' is the wordplay.
'order' becomes 'sort' (I've seen this before).
'includes' means one lot of letters goes inside another.
'unfilled bombe' becomes 'be' (I can't explain this - if you can you should believe this answer much more).
'sort' enclosing 'be' is 'SORBET'.
Can you help me to learn more?
(Other definitions for sorbet that I've seen before include "Fruit juice and water ice" , "Water ice dessert" , "Frozen dessert" , "Flavoured water ice" , "Mushy ice drink to cleanse the palate" .)