Sort of feast including right dessert (6)
I believe the answer is:
afters
'dessert' is the definition.
(afters can mean a dessert course)
'sort of feast including right' is the wordplay.
'sort of' indicates an anagram.
'including' indicates putting letters inside.
'right' becomes 'r' (common abbreviation).
'feast' with letters rearranged gives 'aftes'.
'aftes' placed around 'r' is 'AFTERS'.
(Other definitions for afters that I've seen before include "Dessert course" , "Tiramisu, possibly" , "Possibly fools" , "food for pudding" , "Dessert, sweet" .)