Unsalted spinach ruined fast food (5)
I believe the answer is:
chips
I'm afraid I can't even guess how this answer relates to the clue.
Can you help me to learn more?
(Other definitions for chips that I've seen before include "Betting counters" , "What one eats" , "Short lofted shots (golf)" , "Casino currency" , "Fried potato strips" .)