Fabulist who manufactured soap out East (5)
I believe the answer is:
aesop
'fabulist' is the definition.
(Greek composer of fables)
'manufactured soap out east' is the wordplay.
'manufactured' indicates anagramming the letters.
'out' is an insertion indicator.
'east' becomes 'e' (abbreviation).
'soap' anagrammed gives 'asop'.
'asop' going around 'e' is 'AESOP'.
'who' acts as a link.
(Other definitions for aesop that I've seen before include "Greek fabulist (Tortoise and the Hare)" , "Classic fable writer" , "very old writer" , "A classical fable teller" , "Ancient Greek author of moral tales" .)