Son leaves stressed having returned final course? (7)
I believe the answer is:
dessert
'final course?' is the definition.
(I've seen this in another clue)
'son leaves stressed having returned' is the wordplay.
'son' becomes 's' (genealogical abbreviation for son).
'leaves' suggests deleting specific letters.
'having returned' shows that the letters should be reversed in order.
'stressed' with 's' taken out is 'tressed'.
'tressed' in reverse letter order is 'DESSERT'.
(Other definitions for dessert that I've seen before include "tart?" , "Christmas pudding maybe" , "Fool possibly" , "Spotted Dick is one" , "Sweet, last course of a meal" .)