Paella almost ruined part of a jacket (5)
I believe the answer is:
lapel
'part of a jacket' is the definition.
(I've seen this before)
'paella almost ruined' is the wordplay.
'almost' means to remove the last letter (most of the word but not all of it).
'ruined' indicates an anagram.
'paella' with its last letter removed is 'paell'.
'paell' with letters rearranged gives 'LAPEL'.
(Other definitions for lapel that I've seen before include "Folded back part of jacket" , "Part of a folded back collar" , "Fold of coat" , "Extended part of a collar" , "Lower part of collar on coat" .)