Well-off from work you picked up fast (7)
I believe the answer is:
opulent
'well-off' is the definition.
(thesaurus)
'work you picked up fast' is the wordplay.
'work' becomes 'op' (abbreviation for opus).
'picked up' indicates a 'sounds like' (homophone) clue.
'fast' becomes 'lent' (Lent is a period of fasting in Christianity).
'you' is a homophone of 'u'.
'op'+'u'+'lent'='OPULENT'
'from' is the link.
(Other definitions for opulent that I've seen before include "Wealthy or luxuriant" , "Wealthy or lavish" , "magnificent" , "Luxurious or profuse" , "Wealthy, possessing riches" .)