What's taken up by chef in kitchen? (5)

I believe the answer is:
knife
'what's taken up' is the definition.
I can't judge whether this defines the answer.
'chef in kitchen?' is the wordplay.
'KNIFE' is hidden backwards in amongst the letters.
But, I am unsure how this is indicated.
'by' is the link.
Can you help me to learn more?
(Other definitions for knife that I've seen before include "Eating utensil" , "Cut" , "Cutlery item" , "Sharp tool" , "Silent killer" .)
