Unpromising areas in which son finds things to eat (8)
I believe the answer is:
desserts
'things to eat' is the definition.
(dessert courses)
'unpromising areas in which son' is the wordplay.
'unpromising areas' becomes 'deserts' (areas where it's hard to survive).
'in which' indicates putting letters inside.
'son' becomes 's' (genealogical abbreviation for son).
'deserts' placed around 's' is 'DESSERTS'.
'finds' acts as a link.
(Other definitions for desserts that I've seen before include "Last courses" , "Sweet courses of meal" , "Final courses" , "Sweets" , "Puddings" .)